Certain features characterize the design of fourth- to sixth-century Christian basilicas in the Latin West: a rectangular nave divided into (three) aisles by arcaded colonnades, a high pitched timber roof over the main nave, clerestory windows overlooking the lower roofs of the side aisles, a porticoed narthex or an open-air atrium on the entrance (or "western" end), a semicircular apse on the other (or "eastern" end). But while some design features were common to the standard basilica "form" other architectural elements varied according to region, tradition, liturgical practice, or the wealth of the community or donor of the building.
Thus, although fourth-, fifth-, and sixth-century Christian basilicas in the Roman provinces of Africa, Byzacena, Numidia, and Mauretania follow the standard patterns, they also are marked by a number of distinctive aspects that are particular to the region (although not necessarily unique since some parallels exist in other parts of the Empire, especially in Spain, Gaul, Egypt and Syria). These distinctive features include the following (see the Tabarka mosaic and reconstruction for illustration):
1. The projection of altars deep into the nave, sometimes as far back as the fifth set of columns (depending on the length of the nave) that could be almost to the middle of the main hall. This may reflect a conservative "hold over" from the pre-Constantinian era (Krautheimer -- ex. Aquileia and early fourth-century churches in Syria). The space between apse and altar was usually enclosed and raised. Ambos were virtually unknown in African churches, and the clergy presumably sat in benches in the presbyterium (main apse) during the service, and the bishop apparently spoke from the his seat in the center rear, among his clergy.
2. Large pilgrimage churches that had as many as nine aisles set off by colonnades (Damous el Karita), only rarely with a transept crossing, probably to accommodate pilgrims and direct the flow of traffic. This recalls the four-aisled Constantinian pilgrimage churches of St. Peters, the Lateran, the Church of the Nativity, and the Holy Sepulchre. Note St. Monique is 35x60 meters long and divided into seven aisles and 14 bays; Basilica Majorum is 45x61 and divided into nine aisles and thirteen bays; Damous et Karita is 45x65 and divided into 9 aisles and 11 bays.
3. A triple arch closing the front of the apse -- possibly another "architectural fossil" of pre-Constantinian church building, and reminiscent of the triumphal arches in Rome, Africa, and Gaul.
4. Raised apses that were accessed by a short flight of steps (see Tabarka and Sbeitla, Bellator mosaic) from the nave. This raised floor often projected out from the apse to make a narrow runway part-way down the main aisle (Dermech, Maktar). This raised platform (solea), sometimes was set off by columns or other barriers, which spatially separated clergy from laity within the nave, and sometimes went deep into the nave (Maktar).
From the exterior, most apses (Dermech and Tabarka are exceptions) were squared off, leaving two side rooms that were accessible from apse and or the side aisles. One of these rooms may have been designed to hold the offerings, the other may have held precious objects or clothing for the clergy.
5. A wide variety of shapes and relative locations of baptismal fonts. Rarely in separate baptistery buildings (as in many parts of Italy and Gaul), fonts are sometimes found behind the apse, sometimes to the left of the entrance, and in one case in the midst of the nave. Shapes range from round to cruciform, octagonal to multi-lobed. In addition to the baptisteries, African basilicas also show a wide variety of ancillary rooms (oratories, consignatoria, sacristies?) that may have served supplemental liturgical purposes (the rotunda at Damous el Karita, for example). In at least one case, evidence suggests that an original baptistery may have been redesigned to function as a martyrium (Sbeitla, Jucundus).
6. The burial of honored dead under the main nave, along the aisles, and adjacent to the walls (outside) of the basilicas. Many of the tombs are covered with mosaic markers, or more commonly with inscribed plaques. The most "privileged" dead (clergy in particular) were buried in sarcophagi under the floors of apses, under the altars, or within apse enclosures (Sbeitla).
7. The existence of counter altars and chancels. These were shrines, found in the rear of the main nave and were probably designed to hold or mark relics of martyrs. Their precise liturgical function is still unknown (Haidra). In rare instances, a shrine might be placed in the midst of the nave and covered by an imposing ciborium, and would have been accessible by means of a stair to a crypt (Basilica Majorum -- relics of Perpetua?).
8. The addition of a counter apse at the west (entrance) end of the nave, opposite the main apse and altar. Two apses are mainly found in Africa and Spain, and extremely rare elsewhere. Sometimes these apses were switched when the building was reoriented, and the original apse then became the "counter apse" requiring the building of a new apse (Sbeitla). The existence of counter apses meant that entranceways were usually placed close to the rear, but on the side rather than at the "western end" of the basilica. Atria were rare in African churches. Counter apses and counter altars suggest the existence of accompanying liturgical action that would integrate the different sections of the church in the movements of the rites (Mathews).
9. The addition of a small three-apsed room (tri-conch) either behind the main apse or on the side of the nave, which may have served the purpose of a martyrium (Damous el Karita, Bir Ftouha, Tipasa --Sta. Salsa, Tebessa). In some cases these three-lobed (trefoil) martyria were separated from the church building as a whole by some distance (Hippo).
10. Ecclesiastical complexes rather than autonomous churches (Sbeitla). Such complexes included bishops’ palaces, dwellings for clergy, baths, community banquet halls, libraries, store rooms, oil presses, etc.
Of these distinguishing features, many seem to have significant connections to the cult of the martyrs in the church in Roman Africa and, as such, shed light on the material and liturgical aspects of this important feature of African Christianity. Given the significance of the cult of martyrs in religious practice and theology, we should expect to find that church architecture was adapted to serve the needs of the community in this respect. However, floor plans and archeological remains often raise more questions than provide answers.
Basilicas evolved through the late Roman, Vandal, and Byzantine periods and they were enlarged and often reoriented. Counter apses were added, and what were originally main altars became secondary altars or saints' shrines placed toward the back of the nave. Original apses became places of burial, usually for clergy, but possibly also for important relics, and these were inaccessible. The new altars gradually moved closer to the presbyterium. All these developments must have either required or reflected shifts in the liturgical movements of the clergy, and are logically connected to the growing importance of the martyr cult (e.g., Haidra, Sbeitla).
One wonders whether the clergy incorporated the shrines or burial places only in the festival liturgies that commemorated the saints, or used these architectural features more regularly. Movement back and forth along the main axis of the church (between apses or altars) would serve to unite a space that otherwise would appear to have two distinct worship centers. The gradual narrowing and shortening of altar enclosures also would make it easier for clergy and congregation to pass into the center of the nave and venerate the holy objects.
At the beginning of the fourth century, during and just after the persecutions of Diocletian and Maximian, local martyrs’ relics were apparently deposited in parish churches, either placed in small vaults or crypts just beneath the altar. They also may have been entombed below the floor of the apse, a space which later might become a counter apse-martyrium. As I have said, these remains were inaccessible either to pilgrims or to clergy.
However, toward the end of the fourth century, or during the Vandal period (another period of martyrdom in Roman Africa), relics were deposited or perhaps even transferred to small anterooms, often tre-foil in shape and attached to the side of the basilica, atrium, behind the apse or counter apse, or at some distance from the main basilica. This may have coincided with the period of re-orientation and enlargement of basilicas and the burial of VIP’s in the counter apses. In at least one case (Jucundus), a detached baptistery may have been transformed into a martyrium around the time a newer, larger church was built. The now dis-used baptistery made a convenient, attractive, and symbolically appropriate space for the depositing of the relics of the catholic bishop during the Vandal raids on the town.
Distinguishing between parish churches, cemetery churches, pilgrimage churches, and martyria may create some false categories -- especially in North Africa. Pilgrimage churches might also serve as the main parish church and headquarters of the bishop (e.g., Hippo), and one usually expects these to be inside the city walls and not built over cemeteries. Pilgrimage churches also tend not to places where "ordinary folk" would be buried "ad sanctos" (Damous el Karita or Bir Ftouha vs. Basilica Majorum -- although Damous el Karita was just inside the Theodosian city wall). In any case, these pilgrimage churches (unlike martyria) had fixed altars, usually placed above a buried relic, a great number of aisles, and other features (transepts, ambulatories etc.) built to manage the movements of large numbers of people.
Pilgrimage churches also occasionally had baptisteries attached, suggesting that people chose to be baptized in a special place of a saint (baptism "ad sanctos"), rather than in the local cathedral (e.g., Damous el Karita or Qalat Siman in Syria). Since neither martyria nor pilgrimage churches were sites for ordinary burial, and since the earliest textual evidence for healing at the site of a martyr’s relics comes to us from Uzalis, Calama, and Hippo in the early fifth century, we are also led to wonder what function these sacred centers served, other than to be places to offer reverence to the special dead.
However, even in "ordinary" churches, the excavation of apses usually turned up sarcophagi, which are assumed to contain the remains of clergy or patrons. Martyria, on the other hand, were not buildings with obvious liturgical functions, although they would contain altars for regular celebration of the eucharist. Instead of burials beneath these altars, however, crypts or caskets for relics were more often found in the tri-conchs or ambulatories, as is also true of the pilgrimage churches. In time, most ordinary "parish" churches would come to have their own relics, and they would be placed beneath the altar.
Several important martyrial and/or pilgrimage churches have been cited as examples in this discussion. They include the Carthaginian churches (or church complexes) of Bir Ftouha, Damous el Karita, and the Basilica Majorum; churches in the region of Byzacena including those in Uppenna, Haidra, and Sbeitla; and the Numidian churches of Hippo, Tebessa, and Tipasa (now in modern-day Algeria). Let me focus more closely on five:
1. Damous el Karita:
This basilica was exceptional on several counts. First of all, it is enormous (65 meters in length -- 150 meters over all). Originally a smaller basilica, oriented north-south, it was probably enlarged and reoriented at the end of the fourth or the beginning of the fifth century. The nave is divided into nine aisles and eleven bays and at its western end, a huge semi-circular atrium gives access to a small trefoil martyrium. The large atrium seems to have been designed to accommodate pilgrims paying their respects to the remains of the saints buried in the small shrine. Behind the eastern apse are a number other structures, including a six-aisled hall that contains a small baptistery. Just above and to the northeast of the basilica proper stands a huge subterranean rotunda that would have been covered by a large dome. This rotunda is colonnaded inside, and has an enormous center pool, which may have been intended as a baptistery or perhaps a pool for ablutions.
2. Bir Ftouha:
Bir Ftouha lies on the northwest edge of the archeological zone of Carthage (in antiquity in Carthage’s northern suburbs) -- c. 1 km beyond the Theodosian city wall. Recent excavations here give evidence that this was another large pilgrimage church (not much smaller than Damous el Karita -- 60 meters for the main hall, and also with few ordinary burials), containing a three-apsed martyrial chapel, a wide nave with at least five aisles and an immense apse and ambulatory, and a very interesting annex building just behind the apse and accessible through the ambulatory. The annex building’s design is that of two concave squares bordered by columns and mosaic-patterned corridors. Here was a medallion patterned floor containing birds, bowls, and crosses as well as vases filled with fruit and flowers, At each of the corners were mosaic scenes of does and stags drinking from the four rivers of paradise. The iconography suggests baptism, although the annex does not appear to have a font and is most likely a second martyrium (in addition to the tre-foil martyrium just off the main nave).
3. Tebessa:
The large church and monastery complex at Tebessa (Numidia -- now Algeria) probably dates from the late fourth century, during the reign of Theodosius I. Mosaics covered the floor of the nave and aisles. Opening from a large colonnaded forecourt, the nave is divided into three aisles, with a chancel area marked off between the third and fourth pairs of columns while a second chancel was laid out near the entrance, in the forecourt. A broad staircase descends from the right aisle to a trefoil martyrium, which appears to pre-date the main church by a few decades, and which probably replaced an earlier saint’s shrine. The shrine most probably contains the relics of Crispina and her companions who died during the Diocletianic persecution (Saxer).
4. Haidra:
The church of Candidus, otherwise known at the Basilica of the Martyrs, provides a fine example of a martyrial chancel, which apparently enclosed the relics of some thirty four martyrs who died during the reigns of Diocletian and Maximian. According to Duval and others, this chancel was probably first built to surround the main altar during first phase of building in the fourth century. During the fifth century (Vandal period), the building was reoriented and the eastern apse was added and gradually built into a fully furnished presbyterium. The former chancel area then became a martyrium toward the (new) rear of the building
Two versions of an inscription, one in mosaic and the other in stone, attest to the existence of martyrs’ remains beneath this area. The mosaic inscription is the first, although both are attributed to the sixth century. In the center of the mosaic we read the name of the donor and the circumstances of the martyrdom as well as the depositing of the relics. To the right and left of this inscription are the names of the thirty four martyrs. Beneath the center inscription is a scene of peacocks drinking from a cantharus. The other inscription was found on the inside of the chancel wall itself, and seems to date from the period of reconstruction. The details of the inscription roughly correspond to the center inscription of the mosaic with at least one important omission -- the name of the donor has been effaced from the stone itself.
5. Hippo:
The most significant feature of this ecclesiastical complex is the tre-foil shaped building just to the southwest of the main basilica, and dated to the first part of the fifth century. Accessible by two doors, each of the large niches is flanked by two columns. Although not necessarily a martyrium (this may have been a dining room built by Augustine for his clergy. However, based on analogies with other pilgrimage centers (e.g., Tebessa, Damous el Karita, Bir Ftouha), the design is consistent with a martyrium. According to the documents, a martyrial chapel was built by the deacon Heraclius in 424/5, in order to house the relics of St. Stephen. One other piece of evidence suggests that this is that particular martyrium: a rectangular cavity roughly in the center of the space about 2x2.5 meters in dimension and 1.5m deep -- large enough to serve as a crypt under the altar in the center of the room.
The evolution of basilicas in Roman Africa certainly reflects important liturgical and ritual actions, many of which must have been associated with the parallel evolution of the cult of the martyrs. Although little can be known for certain, and much more interdisciplinary work remains to be done, some basic conclusions can be drawn. Distinct architectural features which were particular to the region, including the double apse and double altar, seem especially designed to serve the martyr cult and to give it prominence in the regular worship life of the community. In addition, both the number and size of pilgrimage churches (Tebessa, Tipasa, Bir Ftouha, Damous el Karita, Basilica Majorum, etc.) suggest the singular importance of shrines of the martyrs, which must have drawn huge crowds from far beyond the local populace. Whether persons visited these pilgrimage centers, or received eucharist (or even baptism) at a martyr’s shrine expected special divine favors is unclear. We do know that something brought them there, if only the opportunity to celebrate their own local heroes and to engage in a festive celebration of their lives.