Introibo Ad Altare Dei—Visual Displaying and Liturgical Ornamentation of Christian Altars in the Late Medieval Illustrations of the Roman Rite

Abstract

This study offers an in-depth exploration of the visual representation of Roman Rite liturgical altars in medieval images from the 13th to the 15th centuries, presenting a fresh perspective on the altar as a central and complex element of medieval liturgical furnishings. It examines key iconographic themes, such as the introit Ad te levavi animam meam and masses celebrated by saints, often depicting divine interventions during the Eucharist. Additionally, the research investigates the role of performative visual elements, such as curtains, which contributed to the depiction of sacred space within altar scenes. These visual devices help convey the altar as a space imbued with spiritual significance. Drawing on a wide range of contemporary visual and documentary sources, the study traces the continuity and variation in the altar’s iconography, offering a nuanced understanding of its role in medieval Christian worship. By examining how artists employed visual symbolism to emphasize the sanctity of the altar, this research sheds new light on the ways medieval altars were imagined and represented in the broader context of medieval art.

1. Introduction1

The verse from Psalm 43 with which this essay opens, Et introibo ad altare Dei, served for several centuries as the introductory dialogue between the priest and acolyte at the commencement of the Eucharistic celebration. The act of approaching the altar of God, of preparing to celebrate the Eucharist by drawing near to the altar, serves as a powerful metaphor for our visual engagement with the Christian altar of the Late Middle Ages. The Christian altar, a multifaceted focal point within the sacred environs of Christian temples, serves not only as the sacred table for the Eucharistic sacrifice but also as a symbolic representation of Christ’s sacrificial nature. Rooted in ancient religious practices, the concept of altars assumes a renewed significance within Christian liturgy, particularly in its association with the profound ritual of the Eucharistic banquet (Rohault de Fleury 1883; Leclercq 1907). Over the span of the past two centuries, scholars have engaged in a comprehensive exploration of various facets surrounding the Christian altar, delving into its morphological variation, topographical placement within the sacred space, liturgical functionality, orientation concerning the congregation, and the diverse ritual artifacts that adorn it (Hassett [1907] 1913; Braun 1924; Webb 1933; Riga 1963; Pocknee 1963; Clayton 1971; Íñiguez Herrero 1978, 1991; Duval 2005).

This research immerses itself in one of the most extensively deliberated elements in the field of liturgical studies (Jungmann [1948] 1951; Lang 2022). Scholars from diverse academic disciplines have found the Christian altar to be a compelling subject, offering insights into its practical uses and the diverse forms it assumes. Sacred archaeology, for instance, diligently reconstructs the external forms of altars based on material culture evidence, establishing connections with ancient sacrificial tables, and illuminating shared elements with Christian altars. The history of religious architecture and archaeology, in turn, trace the evolving relationship between altars and the morphologies of temples and churches, examining how considerations of functionality were sometimes influenced or abandoned due to the prevailing fashions and formal trends of different eras (Viollet-le-Duc 1854; De Blaauw 1991; Sastre de Diego 2007).

Theological inquiries delve into the altar as the sacred table for the Eucharistic feast, a sanctified space where the sacrament of the Mass is instituted. Meanwhile, liturgical history scrutinizes the altar’s role in orientating liturgical actions, revealing passionate debates that have endured through the ages. Legal history, taking an intriguing turn, examines the altar as a space for solemn oaths and as a prominent setting where historically significant agreements were solemnized. Anthropological perspectives identify Christian altars as evidence of the continuity of signs and materials within religious ceremonies, studying the behaviours of liturgical participants in relation to altars and the textual formulas associated with them (Brockman [1934] 1997; Parker 2001; Martin 2005; Bell 2009; Levatois 2012; Heid 2023).

Within the realm of art history, Christian altars have been scrutinized in relation to temple morphology and the arrangement of images (Gardner 1994; Kroesen and Schmidt 2010; Caillet 2005). However, art history, like its counterparts in other disciplines, has traditionally turned to liturgical sources and archaeological evidence to contextualize sacred spaces and the images associated with altars. This research seeks to chart a new course by recreating the form of the late medieval Christian altar primarily through the lens of iconographic sources, thereby contributing a unique dimension to the broader history of medieval art. Among the various types of altars employed in the medieval world, this text will focus exclusively on fixed altars consecrated for Eucharistic use, setting aside the fascinating depictions of portable altars or those adorned with Marian or saintly imagery (Mosby [1957] 1996; Budde 1997; Hahn 2014). The focus extends to visual evidence from the 13th to the 15th centuries, homing in on paintings, manuscripts, and artworks from Western Europe during this period.

Special emphasis is given to those instances where the altar assumes a prominent position within complex figurative programs, enriching our understanding with intricate details. This exploration then takes a deliberate plunge into the codification of the altar within the Roman Rite, considering the uniformity imposed by the Gregorian Reform by the 13th century. Despite regional variations, the functioning and arrangement of altars remained largely untouched by local liturgical idiosyncrasies, as the entirety of Western Christendom prayed in unison under the reformed liturgical formulas.

This research endeavours to delve into the intricacies of late medieval Christian altars by spotlighting the characteristic visual elements employed by painters of the period. The examination of these visual constructions will draw attention to specific typologies of altars, with a particular emphasis on those elucidated in the illustrations accompanying the introit of the First Sunday of Advent (Ad te levavi animam meam). Moreover, this examination seeks to unravel the visual nuances of altars and their associated artifacts within the iconographic themes of miraculous masses officiated by saints, exemplified in the Mass of Saint Gregory. Of particular interest is the exploration of the altar’s visual role as the stage for the transubstantiation of the Eucharistic elements during these sacred events.

Furthermore, the study extends its gaze to the presence of liturgical curtains within visual programs of the Late Middle Ages. Despite the wealth of prior research, details surrounding the role and characteristics of these curtains remain elusive. This investigation aims to fill this gap by scrutinizing their representation in visual narratives, providing insights into their significance within the visual culture of the Late Middle Ages. As such, this research not only aims to contribute to our understanding of the visual representation of Christian altars but also to provide fresh perspectives on the often-overlooked visual elements, such as curtains, that accompanied these sacred furnishings during this period.

It is crucial to acknowledge that this study navigates through a plethora of Christian altars represented in paintings, manuscripts, and artworks from the Western Late Middle Ages. The spotlight is directed towards complex figurative programs where the altar assumes a commanding position, providing a wealth of details for nuanced analysis. However, as we embark on this intellectual journey, a note of caution is sounded. The illuminated manuscripts that have survived through the ages and are currently housed in libraries and museums constitute but a fraction of the medieval book production. Consequently, any conclusions drawn from the analysis of these images must be approached with circumspection, eschewing broad generalizations that might not be universally applicable across temporal or geographical contexts. These findings are inherently provisional and subject to refinement with the discovery of new manuscripts and the emergence of hitherto unconsidered iconographic types.

2. From the Altar to Heaven: Ad te Levavi Animam Meam

One of the earliest iconographic themes in which the Christian altar of the Late Middle Ages assumes particular prominence can be found in certain illustrations that adorn the initial letter marking the introit chant for the First Sunday of Advent. The words Ad te levavi animam meam from Ps. 24 are elaborately ornamented in this liturgical incipit, accompanied in some cases, as in a Missal preserved in Sens,2 by the corresponding score that develops the chant (Figure 1). To achieve this, manuscript illuminators developed a highly significant iconographic type of the Late Middle Ages: the offering of the praying soul. This type manifests in two closely related visual variations, depending on whether or not the image of God the Father appears above. These depictions have been scarcely examined within the historiography of medieval art (Branner 1972; Büttner 1979; Castiglioni 1992).

From a theological perspective, these images are imbued with profound symbolic content, linking the contemplation invoked by the psalmist to the period of anticipation embodied by Advent, as the prelude to Christmas. The introit chant itself reflects this sentiment, conceived as a yearning for the Incarnation that resonates throughout the entire liturgical season. Certain scholars have drawn connections between the illustrations of this iconographic theme and the Crucifixion type traditionally associated with the Te igitur in medieval Missals (McKinnon 1978; Suntrup 1980; Saggese 1999; Gy 1990; Pazos-López 2023). Others have sought antecedents in the imagery of King David presenting his soul to God, as portrayed in psalters (Ragusa 1975).

The visual pattern consistently adheres to a specific formula: a cleric celebrates the Eucharist before the altar, and from his joined hands emerges a representation of his soul, depicted as a homunculus, a small, naked child symbolising purity. This homunculus ascends, gazing upwards towards God when He is present in the image. Accordingly, the figured soul mirrors the cleric’s devout expression, embodying the trustful prayer directed to the Lord. In many depictions of this homunculus, the imagery of the diminutive soul is refined in its ascent toward God, often serving as a symbolic bridge between humanity and the divine. These representations depict the soul as a miniature vessel bridging the human and the divine, connecting the earthly and celestial realms.

One of the most exquisite examples of this visual theme can be found in a Missal from Tours, now preserved in its municipal library.3 In the illustration (Figure 2), the tonsured cleric, vested in the purple chasuble of Advent, clasps his hands and closes his eyes in a prayerful posture before commencing the Mass.

His soul, projected from his hands in a gesture of upliftment, echoes the introit chant’s invocation. In front of the priest lies the altar, towards which the soul is directed: a wooden table adorned with two layers of inner textiles –red and green– topped with a white cloth. Upon this cloth rests the corporal cloth and part of a sacred vessel. Noteworthy here is the retable, crafted in wood and featuring the central type of the Crucifixion, one of the characteristic adornments of altars in the fifteenth century. In the background, the same scene reveals a niche in the wall, functioning as a credence table, where cruets are placed, completing the depiction of a meticulously arranged liturgical setting. Particularly noteworthy is a wooden footstool, crafted from the same material as the altarpiece, which elevates the priest’s position and functions as a theatrical platform. Equally remarkable are the tactile qualities of the altar linens, which captivate not only through their intricate designs but also through the stark contrast they present with the exceedingly rare surviving altar cloths from this period.

The same scene is depicted in a Missal from Lyon, though with a distinctly different arrangement.4 Here (Figure 3), the altar is embedded against a wall, within which an opening reveals the figure of God the Father, replacing the retable.

In this instance, God manifests directly through a window, yet simultaneously, God is transformed into an image, assimilated to the structure of an altarpiece. Within this visual typology, God is not only present in the image but also as the image itself, underscoring the profound theological and symbolic resonance of this transformation. The altar table includes a small predella, designed as a decorative strip adorned with hagiographic iconographic types, harmonising with the ornamental designs directly applied to the stone frontal. At the centre of the altar stands an open Missal, while to the left is the chalice, placed in a position somewhat unconventional for the celebration of the rite. This irregularity reflects a broader tendency among illuminators to eschew strict liturgical accuracy in favour of conveying a clear conceptual synthesis of the scene’s thematic essence. Such interpretative liberties underscore the symbolic priorities of medieval manuscript illumination, privileging theological meaning over ritual precision.

Another Missal, originating in the early 15th century and now housed in the Municipal Library of Valenciennes, presents a particularly intriguing figurative development of the altar.5 In this depiction (Figure 4), the priest is transformed into a supplicant who, like the faithful reciting Psalm 24, directs his soul to God, who receives it from the heavens.

This is not interpreted as a funerary journey of the soul from earth to heaven but rather as a deeply spiritual pilgrimage, wherein the soul is oriented towards God, akin to the trajectory of prayer or the deliberate ordering and directionality intrinsic to worship. In this image, the altar appears as a substantial stone block featuring niches, with the central niche likely serving as an access point to the reliquary compartment beneath the altar stone (ara). The altar cloth drapes across the entire upper surface, with a modest fringe hanging at the front and nearly cascading down the sides. The retable is designed as a pediment with a frieze in the form of an inverted T, devoid of any figurative decoration except for its gilded finish. This austere yet luminous design underscores the symbolic centrality of the altar while offering a visually striking representation of its sacred function.

While most compositions of this theme are found in Missals—books specifically intended for use on the altar—it also appears in other types of manuscripts tailored for particular clerical functions, such as pontifical manuscripts. In these cases, the arrangement of elements is slightly adjusted to incorporate the visual identification of the cleric’s episcopal rank, integrating pontifical insignia into the elevation of the soul. A noteworthy example is an image preserved in a late 14th century Pontifical manuscript belonging to the Bishop of Luçon, housed now in the Municipal Library of Bayeux, which depicts a bishop offering his soul to God (Figure 5).6

In this representation, the homunculus is shown wearing a mitre, mirroring the bishop, symbolising the indelible mark of episcopal consecration upon the soul. Here, the altar table is visually subordinated within the composition, depicted as resembling a sarcophagus draped with a cloth. Of particular interest is the presence of an assisting cleric holding the bishop’s crosier, a detail that adds ceremonial depth to the scene while emphasising the hierarchical and liturgical framework surrounding the central act. This unique adaptation illustrates the versatility of the theme in aligning with different clerical contexts and manuscripts.

This visual theme undergoes a clear variation throughout the Late Middle Ages, warranting detailed examination, as it parallels the full codification of the medieval altar’s directionality. The earliest iconographic representations of this subject emerged in the mid-13th century. Manuscripts from this period, such as a Missal housed in the Municipal Library of Reims7 and an Antiphonary in the Municipal Library of Rouen,8 display an identical arrangement wherein God the Father is positioned above, distinctly separated from the altar itself, while the homunculus is offered directly toward the sacrificial table (Figure 6).

Divine presence resides in the celestial realm, rather than on the immediate horizontal plane of liturgical prayer, a theological perspective aligned with Byzantine liturgical thought. In these representations, God the Father is depicted blessing with one hand while holding the terrestrial orb with the other, portrayed timelessly as the Creator of the universe. Notably, in the Rouen Antiphonary, the homunculus turns its head to gaze directly at God, suggesting that only the soul truly knows where to direct its attention, even when the body and the individual’s earthly consciousness remain unaware. This arrangement appears in at least a couple of other manuscripts from the same period (Branner 1972).

Iconographic depictions of this theme evolved significantly in the 14th century, particularly in the communication between God the Father and the homunculus over the altar, though the divine figure’s position remained largely consistent. Two Parisian Missals, both preserved in the Mazarine Library in Paris,9 include this imagery accompanying the introit for the First Sunday of Advent. In these lateral perspectives (Figure 7), the praying soul emerges from the hands of the cleric, who kneels in adoration before the altar.

Both altars are portrayed as quadrangular marble tables covered with white cloths. One features an altar cross, while the other includes a chalice draped with a purificator cascading down its rear. God the Father appears in a heavenly cloud, blessing the scene and receiving the prayer. A particularly striking example is found in a Parisian Missal now in Lyon, where God the Father is depicted within an architectural canopy, holding the soul as if preparing to take it to Himself.10 Remarkably, in this scene, both the homunculus and the cleric remain focused on the altar positioned to the right, seemingly unaffected by divine intervention.

By the late 15th century, other compositions began to depict the altar in its full liturgical complexity, complete with a wide array of ritual artefacts. These illustrations echo the iconographic arrangement found in the visual theme of the Mass of Saint Gregory. In a Missal preserved in the Abbey of Solesmes (Figure 8), the altar is oriented toward a window in the wall through which the image of God the Father appears.11

However, unlike the recessed altar in Lyon Ms. 515 mentioned earlier, this altar stands apart, with the faithful positioned between the altar and the divine presence. This arrangement introduces a new figurative modality in which both the cleric’s soul and the altar remain directed toward the Lord, while many of the faithful are portrayed observing only the altar, seemingly unaware of the higher reality unfolding above.

A second, more widespread type of representation follows a more traditional design, as seen in two Missals: the Missal of Pierre de Laval in the Archives départementales de Maine-et-Loire12 and a Missal from the Municipal Library of Abbeville.13 These manuscripts share an identical compositional structure. In these depictions (Figure 9), the altar assumes a central, dominant role, adorned with all its elements: retable, cloths, textile frontal, sacra, Missal, and sacred vessels. The homunculus ascends from the priest’s hands to the heavens, where the sky opens to reveal God the Father holding the orb of the world and wearing the papal tiara, depicted as the Eternal Priest and surrounded by angelic choirs. The faithful are shown on either side of the altar. While some observe the soul’s ascent to God, most remain focused on the altar itself, seemingly unaware of the transcendent act taking place.

The diversity of forms assumed by this visual theme reveals how Late Medieval altars were arranged to symbolise the priest’s orientation of his soul toward the Lord. This orientation is not merely a matter of the altar’s physical positioning but reflects a deeper spiritual awareness directed toward a higher reality. The placement of the faithful in various perspectives likely reflects not only compositional choices by the illuminators but also a broader pattern of unity in the directionality of Eucharistic prayer, a subject that has been explored extensively (Lang 2004; Levatois 2012).

3. The Altar and Its Artefacts in Masses Presided over by Saints

The visual culture of the High and Late Middle Ages codified a series of iconographic themes that, some years ago, we classified under the field of masses presided over by saints. These refer to Eucharistic visual motifs where a cleric celebrates Mass at the altar but is distinctly identifiable as a specific saint—whether presbyter or bishop due to certain attributes—or through incorporation into a more elaborate visual programme. Typically, these Eucharistic acts result in some form of miraculous occurrence: the physical manifestation of Christ upon the altar, the appearance of the Virgin Mary, or the enactment of a thaumaturgic event during the celebration of the Eucharist.

The motivations behind depicting saints officiating at Mass were manifold. On the one hand, these images underscored the sanctity aspired to through the sacrament of Holy Orders and the importance of the Mass as the central sacrament of Christian life was reinforced. On the other hand, the inclusion of miraculous events during the liturgy served to legitimise the real presence of Christ in the Eucharist and reinforced its role as the central sacrament of Christian life. Iconographic themes include the Mass of Saint Erhard, the Mass of Saint Basil, the Mass of Saint Clement, and the Mass of Saint Ambrose (to name but a few), which represent some of the earliest developments of this theme and have been extensively examined in a recently published monograph (Pazos-López 2023, pp. 195–210). Moreover, the depiction of saints celebrating the Eucharist serves to legitimise the clerical Eucharistic function, reinforcing the obligation established since the Gregorian Reform for all priests to celebrate a daily Mass.

A secondary subset of these images falls under what we term miraculous Masses, instances where divine intervention occurs during the liturgy. Among these, the Mass of Saint Martin of Tours was particularly widespread in Romanesque Art. Another notable example is the Mass of Saint Giles (Figure 10), as depicted in a late-15th-century panel painting housed in the National Gallery, London (Friedländer 1937; Hinkle 1965; Girault 1994; Colenbrander and Girault 1997). Both the narrative and visual arrangement of this piece are of significant interest. It recounts the story of Charlemagne beseeching Saint Giles to intercede for divine forgiveness for a sin too great for him to confess. Saint Giles offers the Eucharist, invoking divine intercession and seeking God’s favour on behalf of the king. At the moment of consecration, an angel descends upon the church altar, delivering forgiveness to Charlemagne in the form of a papal bull held in its hand. This rich interplay of liturgical symbolism, saintly mediation, and miraculous occurrences highlights how the Eucharist was visually and theologically framed as a profound site of divine–human encounter in medieval spirituality.

Beyond the miraculous event and its basis as one of the saint’s life scenes, the image of the Mass of Saint Giles is of great interest for understanding the way in which altars were represented at the close of the Middle Ages. The altar in this scene is a fixed piece of furniture, draped with an antependium made of cloth and adorned with a decorative textile border, above which rests the altar cloth. Attached to the altar is a retable, in which inlays of precious stones are visible, and was probably originally an altar frontal (Van der Ploeg 2002, p. 108; Sadler 2018). Above this retable decoration, a cross, also embellished with gems, presides over the entire altar arrangement and has been linked to the lost Saint Eloy cross from the Treasury of Saint Denis (Salet 1942; Murphy 2020, pp. 48–49). The presbytery space is further adorned with four columns featuring angelic figures, although only one is visible in the scene (Biebel 1950). From these columns come the rails that support green curtains, which we will discuss further below. Equally noteworthy is the meticulous depiction of the cushion upon which the Missal rests, as well as the detailed rendering of the liturgical book itself, open upon the altar. The Missal is placed on a velvet cloth cover, reminiscent of those used in the Middle Ages to protect valuable manuscripts, further underscoring the reverence and care afforded to sacred objects in this period. These elements allow us to evoke the manner in which altars were represented in the final years of the Middle Ages. Additionally, the abundant presence of gemstones and precious stones demands attention, underscoring the sumptuousness of the Treasury of Saint Denis (Virdis 2022). This opulence aligns closely with the predilection for material splendour in the liturgy, a hallmark of Abbot Suger’s aesthetic sensibilities.

However, the most widely diffused iconographic theme of the miraculous Eucharist presided over by a saint was the Mass of Saint Gregory. Its vast popularity, both in the Iberian Peninsula and Northern Europe, can be explained by the devotional importance assigned to the Eucharist during the medieval period, as well as by the explicit depiction of the miracle of transubstantiation in a visible manner (D’Altena 1959; Bynum 2006; del Pozo Coll 2009; Angenendt 2014). The tradition justifying the origin of this theme is based on the doubt raised by an acolyte assisting the Pope—or, according to some sources, by a laywoman attending the Mass—regarding the true presence of Christ in the Eucharistic species. The scene is almost always attributed to the Basilica of Santa Croce in Gerusalemme in Rome, and the presence of Pope Gregory is linked to the Gregorian reform, a process much later than the papacy of Gregory the Great, but legitimised in the eleventh century under his name. The rising Eucharistic devotion of the thirteenth century, which contributed to the establishment of the feast of Corpus Christi, undoubtedly inspired the creation of this visual theme, which centred on the celebration of the Eucharist (Rodríguez Rodríguez 1998; Hecht 2005; Lentes and Gormans 2007).

In all the preserved examples, the arrangement of elements remains consistent: Pope Gregory celebrates the Eucharist, and at a moment of the consecration, the corporeal image of Christ appears on the altar, often surrounded by the arma Christi or instruments of the Passion (Berliner 1955). One of the interesting examples we will examine is a Spanish panel painting held at the Metropolitan Museum of Art in New York (von Sonnenburg 1993/1994; Vega-McTighe 2011). Its small size, less than one meter, and the framing in a cut-out panel suggest that it may have been part of a larger altarpiece with a more expansive iconographic programme. The image (Figure 11) depicts Pope Gregory in the act of genuflecting after the consecration of the wine. Above the altar, a miniature figure of Christ, depicted as the Man of Sorrows, sheds His blood over the chalice, with a stream flowing from His side directly into the cup.

Behind the saint, two assisting deacons hold the ends of the chasuble, decorated with rich damask patterns, while carrying lit candles as a sign of respect for the moment of consecration.

The altar table in this image is imbued with profound symbolic and artistic significance, with its detailed representation inviting careful examination. The stone base, adorned with intricate mouldings, supports an altar covered with a textile frontal and bordered by fabric appliqués. These are overlaid with a white linen cloth, evoking the holy shroud by symbolically receiving the blood from Christ’s wounds at His feet. On the altar, essential liturgical objects are meticulously depicted: the chalice, a simple paten bearing the consecrated Host, and a purificator adorned with red embroidery that complements the altar cloth’s decorative motif. The linteamenta altaria are rendered with extraordinary precision, allowing for the identification of multiple layers of altar linens. These include a textile frontal and distinct altar cloths, each distinguished by unique weaving patterns and formats. Among these details, a small-sized palla corporalis (corporal) is clearly discernible, as is a fringed purificator, with its distinctive design draped elegantly over the altar (Izbicki 2016).

To the left, depicted in the image’s perspective as being further back, the Missal can be seen, open to the Te igitur page—illustrating the Crucifixion—along with the papal tiara, identifying the figure presiding over the Eucharist. To the right, a small pedestal supports metal cruets. Additionally, above the altar, a retable serves as a backdrop, and at the rear, the liturgical curtain is opened, revealing the instruments of the Passion that have already been mentioned. The intercession of the Virgin Mary is symbolized in the stained-glass window behind, though she does not directly intervene in the miraculous event being depicted.

Another panel painting depicting the Mass of Saint Gregory is currently housed in the Museum of Burgos, most likely originating from the Church of Cogollos (Silva Maroto 2003, 2006). This work (Figure 12), by the painter Pedro Berruguete, influenced by the Italo-Flemish style in his later Castilian period, divides the composition into three distinct spatial realities in a very original way. In the foreground, the clergy gather around the altar, including assisting deacons, cardinals, and officials from the Roman Curia who are present. In the middle ground, the miracle occurring on the altar is depicted, with the corporeal presence of Christ before the sacred host on the cross. The background features souls from purgatory being rescued by God, under the timeless iconography of the Eternal Father, visible through an open portal. This portrays the idea that, through the sacrament of the Eucharist, Christians can be saved and attain eternal life (Palazzo 2014b; Kumler 2015).

Two liturgical artifacts are present in the foreground, though with little clarity: a situla and an aspergillum for sprinkling holy water, and a holder for torches, likely used to place one of the candles held by the deacons. The altar is adorned with cloths and textiles, although with less intricate detail regarding the altar vestments compared to the previous panel, as only a white linen altar cloth and a corporal are visible. Nevertheless, the fundamental liturgical objects are once again prominently displayed: the Missal, the chalice, the paten, and the papal tiara. Only two candlesticks at the ends and a triptych with the Roman Canon’s formula, which will later take the form of an altar card, are added. The significance of these altar cards, originally conceived as simple pieces of parchment, as seen in the composition, would eventually give way to altar cards with ornate metal frames.

The practice of piling so many liturgical items on the altar does not seem to be driven by a purely practical concern but rather serves as an opportunity for the artist to showcase their mastery of detail, a characteristic common in Flemish painting of the 15th century. The clerical vestments depicted in this panel hold significant prominence, encompassing both the liturgical garments of the celebrant and ministers and the religious attire of the cardinals and other clergy of the Roman basilica. Saint Gregory’s chasuble, rendered in vivid red, is lifted by the deacons to facilitate the genuflection with which he venerates the consecrated Host, allowing a glimpse of the alb beneath, adorned with auriphrygia or grammata at its lower hem.14 Meanwhile, the deacons are attired in green dalmatics, richly embellished with gold decorations and featuring collars fastened with corded clasps (Pazos-López 2015, 2019).

The last example we will discuss is housed in the Museu Nacional d’Art de Catalunya, a version of the same Mass of Saint Gregory, but interpreted this time by the painter Diego de la Cruz, in the final two decades of the 15th century (Quílez i Corella 2003; Estrada-Rius 2009). We will not repeat the elements we have already identified in previous examples. What is interesting in this image are the many details hidden within the altar itself. For this particular scene (Figure 13), the altar is represented as a stone table with a side niche. In this niche, the cruets that were seen in earlier images on a side shelf are placed. The armrest of a kneeler serves as support for the papal tiara, which no longer rests on the altar table. Instead, on the altar cloth, we see a punched paten, a beautiful decorative detail that was not present in the previous examples. The surface is marked with divisions for dividing up the sacred particles, etched through a special technique in the design. The candlesticks placed on the altar are more ornate, but the deacons’ candles have been replaced by simple torches. Above the altar, there is a small jug with a plate: it is not a lavabo for the celebrant’s hands, but rather the jar of vinegar offered to Christ on the cross, a reference to the elements of the arma Christi, together with the three nails that also rest on the altar.

The iconographic representations of the Mass of Saint Gregory provide a true visual delight, offering a rich opportunity to identify the liturgical artefacts placed within the sacred space of the altar during the celebration of the Eucharist. The painters’ desire to include as many details as possible renders these images an invaluable treasure for understanding the morphological uses of altars, particularly in their capacity to house additional storage spaces, such as credence tables and niches, alongside their role as opulent settings adorned with multiple layers of textiles. These textiles are often richly combined, juxtaposed with cloths directly in contact with the Eucharistic species, such as corporals and purificators (Izbicki 2016).

Moreover, the sumptuousness of the liturgical vestments depicted in these works reveals an almost complete codification of the liturgical ornaments that, throughout the Modern Era and well into the 20th century, were used in the service of Christian liturgy. These garments, embellished with intricate embroidery, appliqué, and unique fabrics, underscore the considerable financial investment made in the furnishing of sacristies in the most significant cathedrals, monasteries and centres of worship. Yet, despite their prominence in the paintings, very few of these vestments have survived to the present day, making the visual representations of the period even more essential for understanding the history of liturgical practice and the continuity and variation in religious rituals during the Middle Ages (Pazos-López 2015).

4. The Altar in the Contemplation of the Latens Veritas

When Thomas Aquinas likely composed the poem Te devote laudo in the 13th century—later known as Adoro te devote and set to music in the 17th century as a Eucharistic hymn—he referred to the Christian God as latens veritas, that is, a hidden or concealed truth within the Eucharist. This concept of the Eucharist as a mystery, wherein God becomes incarnate within the Eucharistic species and “hides” from corporeal sight, reached its zenith during the same century, coinciding with the gradual rise of Eucharistic devotion fostered by the codification of the feast of Corpus Christi. Visual evidence from iconographic themes associated with the late medieval Christian altar offers invaluable insights into how this “hidden truth” of the sacrament was materially expressed through sensory experience. By examining these representations, one can discern how the theological concept of the concealed divine presence was rendered palpable, engaging both the faithful’s visual and contemplative faculties in the veneration of the Eucharistic mystery.

A noteworthy element that served to obscure the visibility of the Eucharistic species —and thus to conceal part of the Mass from the faithful—is the use of altar curtains, referred to in medieval sources as cortinis, pannum, velum, tetravela, and, sometimes, pallia (Lane 1975, 1984, p. 55; Duffy [1992] 2022, p. 96; Schimidt 2007; Sciacca 2007). Numerous liturgical images from the Late Middle Ages depict visual arrangements of the altar in which lateral curtains are prominently featured. These depictions, however, stand in stark contrast to the paucity of written sources that explicitly document the use of such curtains within medieval liturgical practices. Despite this, the history of Christian liturgy exhibits significant resistance to acknowledging the use of liturgical curtains in the Western tradition (Braun 1924, vol. II, pp. 167–68; Jungmann [1948] 1951, vol. II, p. 794).

The primary reason for this reluctance lies in the absence of rubrics within Missals and Sacramentaries specifying the appropriate moments for drawing and retracting such curtains. Indeed, while some medieval written sources do document their use, it is likely that this practice was confined to the realm of traditional ritual customs and local conventions rather than representing a fully established liturgical norm. Joseph Braun and Josef Andreas Jungmann, for instance, note the existence of curtains in Eastern rites, employed to shield the faithful’s gaze during the Canon of the Mass. However, they assert that in the Western tradition, there is no record of a consistent practice of concealing the consecration from the congregation using curtains. Nevertheless, they do acknowledge and justify as a customary practice in certain regions during the late Middle Ages the drawing of lateral curtains either at the commencement of the consecration or at the beginning of the Mass itself.

Supporting this assertion, numerous iconographic depictions of late medieval altars reveal the presence of side curtains complete with their corresponding canopies, rings, and drawstrings. One might ask, then, what purpose these abundant representations of veils as “fictitious” artefacts could possibly serve. Why would altars be adorned not only with curtains but also with elaborate mechanisms for their proper operation, if these systems did not play an active role in the liturgical practices of the time? The recurring presence of lateral curtains in these images suggests a deliberate and meaningful integration of these textiles into the visual and symbolic language of the liturgy. Far from being mere decorative elements, these curtains likely fulfilled both practical and symbolic roles. Their use in enclosing the altar during specific moments of the Mass—particularly during the Eucharistic Canon—aligns with the medieval emphasis on veiling the divine mystery from the laity, reinforcing the sacredness and inaccessibility of the consecration. This practice, though absent from the rubrics of contemporary Sacramentaries and Missals, finds its justification in the iconographic sources, which offers a window into the lived experience of medieval worship (Sinding-Larsen 1984; Kessler 2019).

Although this practice is not corroborated in the rubrics of the Missals of the period, written sources from medieval allegorists allude to the presence of such curtains, often assigning them symbolic attributes. Honorius of Autun, writing in the 12th century, notably contributes to this interpretative tradition by offering allegorical readings of these veils:

De palliis. Pallia, quæ in Ecclesia suspenduntur, sunt miracula Christi, quæ in Ecclesia leguntur.15

(Honorius of Autun, Gemma animae, Ch. CXXXVII)

Several years later, Sicardus of Cremona referred to the curtains among the various textiles adorning the temple, discussing the symbolic significance of the colours used in some of these draperies. An example of such coloured curtains can be observed adorning the windows of the apse in the Basilica of Saint Denis, as depicted in the Mass of Saint Giles at The National Gallery:

Ornantur et altaria et Ecclesiae palliis, cortinis et hollosericis, et lineis, tapetibus historiatis, coronis regalibus, aut aliis ideis, aut diversis characteribus insignitis; quae omnia pertinent ad Christi miracula, vel ad futuram gloriam, quae ex antiquorum exemplis, et meritis nostris, imo gratiae Dei multifariis et fructuosis operibus revelabitur in nobis. […]

Ergo pallia vel cortina candida munditiam, rubea charitatem, viridia contemplationem, nigra carnis morlificationem, variala coloribus virtutum varietatem, linea tribulationem, holloserica significant virginitatem, ut per visibilia ad invisibiles moveamur ornatus, et repositam in coelis gloriam avida mente quaeramus.16

(Sicardus of Cremona, Mitrale, Ch. XII)

By the late 13th century, William Durandus expands upon the description of these liturgical curtains in his Rationale Divinorum Officiorum, specifying their number and placement throughout the temple, as well as identifying the liturgical occasions during which these veils are to be displayed, as shown below:

Circa hoc autem notandum est, quod triplex genus veli suspenditur in Ecclesia, videlicet, quod sacra operit, quod sacrarium a clero dividit, et quod clerum a populo secernit. Primum est nota nostrae legis. Secundum nota nostrae dignitatis, quia indigni sumus, imo impotentes coelestia intueri. Tertium est coercitio nostrae voluptatis carnalis. Primum, videlicet cortinae, quae ab utroque altaris latere extenduntur sacerdote secretum intrante, prout in quarta parte, sub titulo “De secreta”, dicetur, significatum est in hoc, quod sicut legitur Exod. 34, Moyses posuit velamen super faciem suam, quia filji Israel claritatem vultus ejus sustinere non poterant, et sicut dicit Apostolus, hoc velamen adhuc hodie est super corda Judaeorum. Secundum, videlicet cortina quae in quadragesima in officio Missae ante altare extenditur, significatum est in hoc, quod velum infra tabernaculum erat suspensum, quod dividebat sancta sanctorum a sanctis, ut dicetur in prooemio quartae partis, per quod arca populo velabatur, et erat miro opere contextum, et pulchra varietate distinctum, quod in passione Domini scissum est, et illius exemplo hodie cortinae varia pulchritudine texuntur. De praemisso velo, et quales debent esse cortinae, habetur Ex 26, 36.17

(William Durandus, Rationale Divinorum Officiorum, Book I, Ch. III)

Later in the same volume, an explicit reference is made to the curtains positioned on either side of the altar, specifying the precise moment during the Canon when this ritual gesture is to be performed, as shown below:

Ad hoc etiam significandum sacerdos secretam intrans, quasi velatur quibusdam cortinis, quae sunt in lateribus altaris, prout infra dicetur in quarta particula canonis, super verbo Hanc igitur. Dicitur etiam Secreta, quia secrete et sub silentio dicitur; Christus enim ad consecrationem corporis sui venturus, secrete, et solus orabat ab hora coenae, usque dum suspensus est in cruce, quas orationes Secretae significant.18

(William Durandus, Rationale Divinorum Officiorum, Book IV, Ch. XXXV)

The written examples selected here not only attest to the presence of curtains and veils in the vicinity of altars during the High and Late Middle Ages but also offer compelling insights into their movement during ritual actions. While it is impossible to confirm the existence of entirely liturgical usage—prescribed by ritual norms and adhering to universally applied paradigms across all times and places—there is ample evidence of a specific practice within many locales of the Late Medieval Roman Rite. This practice underscores a performative use of the altar that intersects sacramental liturgy, devotional observance, and popular piety, much like the contemporaneous custom of opening and closing certain wings of Gothic altarpieces (Ehresmann 1982; Williamson 2004; Van Tongeren 2009; Petersen 2014).

When reflecting upon the use of veils and cloths that are ritually unveiled and drawn back during liturgical ceremonies, it is imperative to also consider the seasonal or temporal significance attributed to such practices. This encompasses, for instance, the veils traditionally employed to shroud sacred images during Lent or on Good Friday, as well as the symbolic act of the stripping of the altars (Tammen and Böse 2012; Lohfert Jørgensen et al. 2015). The latter, immortalised in the seminal work of Eamon Duffy ([1992] 2022), highlights the profound transformation of religious practices in late medieval British society, charting the decline of Catholic liturgical traditions and their subsequent replacement with Protestant forms of worship. These seasonal veils, imbued with theological and devotional resonance, served as powerful instruments to mediate the spiritual journey of the faithful through the liturgical calendar, marking periods of penance, mourning, and reflection. However, it is worth noting that such veils, laden with temporal significance, do not appear to be the central motif in the visual depictions of late medieval altars. The iconographic representations of veils in these contexts seem to fulfil a different symbolic and functional role, distinct from the liturgical customs tied to specific seasons. Instead, they evoke a performative and aesthetic dimension within the ritual space, illustrating practices that transcend the episodic rhythm of the ecclesiastical year. These depictions, therefore, invite a nuanced interpretation that separates them from the explicitly temporal veils of penitential observance, anchoring them instead within the broader framework of medieval ritual aesthetics and their complex interplay with the sacred and the sensory.

The concept of veiled contemplation, or contemplation through curtains, finds substantial iconographic support in examples from the Late Middle Ages. One of the most intriguing instances is a 14th-century manuscript of Le Pèlerinage de Vie Humaine by Guillaume de Digulleville (Figure 14), which presents an intriguing depiction of Moses celebrating the Eucharist behind a liturgical drapery, aiming to establish a connection between the Old Testament priesthood and the clerical functions of the Christian Church.19 The illuminator carefully renders the verdant-hued curtain, artificially drawn aside to the right, as if discreetly inviting the viewer to glimpse the ritual action occurring behind it. This scene, which centres on the doxology with the ciborium raised aloft, evokes a sense of revelation, as though the curtain frames an otherwise hidden spiritual window into the sacred proceedings. The visual perspective introduces an intriguing interplay, as the altar is depicted at an oblique angle oriented toward the right, with the bishop Moses and the acolytes positioned in a slightly tilted arrangement. In contrast, the curtains do not appear to integrate seamlessly into the compositional framework of the altar. Instead, they align with the layout of the manuscript’s miniature, as if functioning not merely as a ritualistic element within the depicted scene but also as a deliberate feature of the manuscript’s design and page architecture. Were it not for the textual references within the layout identifying the figure as Moses, it would be nearly impossible to discern his identity solely through the image. Such devices underscore the interplay between text and image in the interpretation of specific scenes, with visual motifs serving as powerful catalysts for extratextual meanings. This intricate interplay between text and image is both common and pervasive across a multitude of liturgical illustrations.

A new depiction of the Mass of Saint Gregory (Figure 15), included within the visual programme of a 15th-century French Book of Hours, presents this narrative in a manner closely resembling the description previously outlined.20 The sacred Host is elevated at the moment of Christ’s apparition, depicted emerging from a tomb positioned behind the altar and supported by an angel. Another angelic figure enters the composition, descending from the heavens while holding the papal tiara, thus revealing that the celebrant is Pope Gregory and facilitating an accurate identification of the visual typology. The altar space is encircled by four tall candlesticks, of which only three are visible, while a curtain frame links the candlesticks in pairs as did the angelic columns of the Mass of Saint Giles discussed above. The curtains entirely enclose the lateral space, cascading fully downwards to obscure the process of transubstantiation by which the Eucharistic species are transformed into the Body and Blood of Christ.

The iconographic representations from as early as the fourteenth century unequivocally attest to the presence of curtains within liturgical settings. While this practice may be attributed to an Oriental influence, the architectural configuration of Eastern altars—situated beneath quadrangular baldachins—fails to account for the integration of rails facilitating the movement of these veils, which were most likely intended to obscure the latens deitas. A distinct category of images portrays specific moments of the Canon of the Mass, with the curtains enclosing these solemn intervals without necessarily adhering to a specific pattern of curtain opening or closure. Such depictions were frequently employed to illustrate certain French Missals, including one preserved in the Bibliothèque Mazarine in Paris.21

In this manuscript (Figure 16), a cleric is shown bowing before the offerings with hands clasped in prayer, assisted by two deacons. The altar is rendered as an imposing wooden structure, draped with at least two layers of altar cloths: an undercloth with a blue border harmonising with a pendant baldachin and a white linen cloth adorned with lace trim. Resting atop these textiles are clearly delineated liturgical elements: the corporal, the chalice, a purificator, and the palla. From the far side of the altar (distant from the viewer’s perspective), a horizontal frame is affixed to the altarpiece, which is richly adorned with small sculptures of saints protruding from the upper structure. Suspended from this frame are curtains of a muted purple hue, secured by a golden cord, further enhancing the solemnity of the depicted ritual moment. This illustration also offers an intriguing detail in the depiction of the wood grain, both in the altar furniture and in the baseboard of the podium upon which it is situated. This decorative aspect, overlooked in earlier illustrations, provides yet another example of the material composition of these liturgical furnishings, shedding light on their construction and the artisanal techniques employed in their creation.

In another manuscript from the same library, a collection of the Decretals of Pope Gregory VIII, includes an illustration of the consecration of the bread (Figure 17), in which a young assistant lifts the celebrant’s chasuble to facilitate his genuflection while holding a lit candle.22 This gesture is of particular relevance here because the altar curtains are depicted in the same colour as the celebrant’s chasuble, albeit with differing decorative patterns: the curtains feature small gold-dotted circles that reveal a textured weave in the fabric, while the chasuble displays more intricate geometric motifs, likely emulating the technique of embroidery. The perspective in this scene is noteworthy, as it permits the visibility of the curtains on the left side, in contrast to the previously discussed image in a Missal, which only revealed the curtains on the right. In this instance, the left-side curtains are shown fully extended and fastened to the frame at specific attachment points. Moreover, it is the elevated and angled perspective that allows for a comprehensive view of all the elements of the altar. In this instance, unlike other previously discussed examples, only the chalice and the Missal are depicted upon the altar, which is draped with a cloth featuring a greyish diamond-patterned texture. The sacred linens, such as the corporal cloth or purificators, are notably absent, likely omitted as part of a visual simplification process.

A depiction of the Mass of Saint Gregory (Figure 18), preserved in a Book of Hours in the Municipal Library of Tours, portrays the liturgical curtains fully deployed aside at the moment of Christ’s corporeal appearance above the altar.23 Saint Gregory, kneeling in reverence, gazes at the real presence on the Eucharistic table while elevating the consecrated Host. The altar depicted in this scene is adorned with a green textile frontal featuring golden embellishments, likely meant to evoke intricate embroidery. A linen cloth with a diamond-shaped pattern covers the altar’s surface, and the sacred vessel—a chalice and a ciborium used for administering the Eucharistic bread—are positioned directly upon it on the right-hand side without the presence of the corporal clothes and purificators, while the left side displays an open Missal with no illustrations. The perspective of this image is intriguing; despite its volumetric inaccuracies, it evokes a sense of symmetry by presenting the altar as trapezoidally open towards the foreground, with both curtains fully extended. As in some of the previous images, the colour of Saint Gregory’s chasuble is paired with that of the curtains, yet without any apparent symbolic relation.

A second category of images depicting curtains relates to the Israelite altar of burnt offerings, visually reimagined as an altar within a Christian church, serving as a means of prefiguring the Old Testament tradition through images that evoke the Church. A good example can be found in a fourteenth-century manuscript of Gratian’s Decretum (Figure 19a), preserved in the Mazarine Library in Paris.24 This depiction features a complete architectural framework of the temple, formally analogous to a Christian church. Moses and Aaron are shown kneeling with their hands extended in prayer, imploring God, who does not manifest visibly in this instance. The altar, prepared for the Eucharist, is a stone structure elevated on two steps. It is draped with a textile displaying visible ornamental colours on its frontal side, overlaid with a white linen cloth hanging over the sides. Curtains are visible only on the left side of the altar, as the lateral perspective obscures the right arm of the framework. Here, the veil fabric is depicted in a muted green tone, fastened to the frame with light-coloured rings.

The same Old Testament theme, framed within a Christian temple, is explored in an illuminated Bible housed in the Municipal Library of Lyon (Figure 19b), which depicts God speaking to Moses, who approaches with animals to offer a sacrifice upon the altar.25 However, this altar is not a monumental stone structure typical of the Old Testament temple; rather, it mirrors the format observed in the aforementioned French Missals. In this instance, the curtains are rendered in a muted violet hue, secured to the frame with a braided gold cord, revealing a diversity of techniques employed in the design of such accessories, which likely aligned with material examples of curtains that have not survived to the present day.

These visual examples of liturgical curtains underscore a ritual practice—the drawing and withdrawing of veils—closely associated with the concealment of the divine mystery within the Eucharist. These elements are not central to the rite itself, as are the positioning of the clergy, the use of specific vestments, or the depiction of sacred vessels. Instead, they contribute to the atmospheric setting of ritual scenes, attesting to the presence of curtains, veils, and hangings with functions clearly determined by liturgical purposes, despite their omission from the rubrics of liturgical books.

The visual emphasis on curtains, combined with other textile elements such as altar cloths and frontals, underscores the tactile and aesthetic dimensions of medieval worship. The richly adorned altars, complete with intricate embroideries, lace borders, and coordinated textiles, reflect a liturgical ethos deeply attuned to the materiality of the sacred. These artefacts, as seen in illuminated manuscripts, painted panels, and other visual media, serve not only as liturgical instruments but also as vehicles for conveying theological truths and evoking sensory engagement among the faithful.

The scarcity of written sources regarding the liturgical use of such curtains also invites reflection on the transmission of ritual practices in the medieval period. Much of what we understand about medieval worship relies on the interplay between written rubrics, oral traditions, and visual representations. The latter, in particular, provide invaluable insights into aspects of the liturgy that might otherwise remain obscure. They capture nuances of local custom and ritual innovation that were never codified, revealing a dynamic and context-sensitive approach to worship (Palazzo 2014a; Pazos-López 2017).

5. Conclusions

In concluding this study, it is imperative to reflect on several key considerations that enhance our understanding of late medieval altars within the sphere of influence of the Roman rite. First and foremost, the artistic image emerges as an invaluable source for reconstructing the ritual culture of the Middle Ages. Numerous aspects, such as the arrangement of objects, the presence of artefacts like curtains, and the extensive use of textiles to embellish the altar’s surface, find their most compelling documentation in the iconographic representations of the period. These images serve as a visual chronicle, capturing the nuances of liturgical practice, material culture, and ceremonial aesthetics that textual sources alone cannot fully convey. Beyond their illustrative function, they act as a form of “visual testimony”, preserving the practical and symbolic dimensions of medieval liturgy.

Furthermore, the thematic exploration of iconographic programmes—such as miraculous masses presided over by saints, the offering of the soul to God, and the intricate depiction of textiles, including curtains—enriches our understanding of the medieval altar’s configuration, craftsmanship, and functionality. These elements also illuminate the interplay between the altar and other ritual devices, revealing how they collectively shaped the aesthetic and sensory experiences of medieval Christian worship. Through such visual artefacts, we gain insights into the complex interplay of form, function, and symbolic resonance in the material culture of the liturgy. The integration of iconographic analysis with written sources is thus indispensable for a nuanced comprehension of medieval rites, offering a framework through which we can discern the theological and cultural underpinnings of these ceremonial practices.

In addition, the depictions of liturgical scenes in panel paintings and illuminated manuscripts shed light on key aspects of medieval spirituality, particularly in relation to the orientation and diversity of liturgical prayer. These images underscore the multifaceted nature of medieval worship, a period characterised by a rich plurality of ritual forms, wherein local liturgical practices often intermingled with popular devotional customs. The depiction of altars adorned with textiles, sacred vessels, and veils reflects not only the aesthetic sensibilities of the period but also the theological and communal dimensions of worship, wherein the material and immaterial aspects of the rite converge.

One of the most striking revelations from this analysis is the role of the oral and performative dimensions of medieval liturgy, often absent from the formalised rubrics of liturgical books. These elements, transmitted through communal memory and practice, underscore a lived liturgy that prioritised the experiential engagement of clergy and laity alike. Such practices highlight the dynamic and participatory nature of medieval Christian worship, transcending the mere formal repetition of prescribed gestures and texts. Instead, they reflect a liturgical culture deeply rooted in sensory perception, communal interaction, and the embodied enactment of sacred mysteries.

In conclusion, the visual and material culture of late medieval altars, as evidenced in the illustrations of manuscripts and panels, offers a profound lens through which to examine the confluence of ritual, art, and devotion in the medieval Roman rite. By integrating the analysis of these iconographic programmes with written and oral traditions, we can reconstruct a holistic vision of medieval liturgy as a dynamic interplay of theological symbolism, artistic expression, and communal experience, deeply embedded in the spiritual life of the Middle Ages.