Fig. 7.—Plan of Basilica adjoining the Forum of the Roman city at Silchester, Hants. (From Archaeologia, vol. liii.)
An early Christian basilica may be thus described in its main features:—A porch supported on pillars (as at S. Clemente) gave admission into an open court or atrium, surrounded by a colonnaded cloister (S. Clemente, Old St Peter's, S. Ambrogio at Milan, Parenzo). In the centre of the court stood a cistern or fountain (cantharus, phiale), for drinking and ablutions. In close contiguity to the atrium, often to the west, was the baptistery, usually octagonal (Parenzo). The church was entered through a long narrow porch (narthex), beyond which penitents, or those under ecclesiastical censure, were forbidden to pass. Three or more lofty doorways, according to the number of the aisles, set in marble cases, gave admission to the church. The doors themselves were of rich wood, elaborately carved with scriptural subjects (S. Sabina on the Aventine), or of bronze similarly adorned and often gilt. Magnificent curtains, frequently embroidered with sacred figures or scenes, closed the entrance, keeping out the heat of summer and the cold of winter.
The interior consisted of a long and wide nave, sometimes as much as 80 ft. across, terminating in a semicircular apse, with one or sometimes (St Paul's, Old St Peter's, St John Lateran) two aisles on each side, separated by colonnades of marble pillars supporting horizontal entablatures (Old St Peter's, S. Maria Maggiore, S. Lorenzo) or arches (St Paul's, S. Agnese, S. Clemente, the two basilicas of S. Apollinare at Ravenna). Above the pillars the clerestory wall rose to a great height, pierced in its upper part by a range of plain round-headed windows. The space between the windows and the colonnade (the later triforium-space) was usually decorated with a series of mosaic pictures in panels. The colonnades sometimes extended quite to the end of the church (the Ravenna basilicas), sometimes ceased some little distance from the end, thus admitting the formation of a transverse aisle or transept (St Paul's, Old St Peter's, St John Lateran). Where this transept occurred it was divided from the nave by a wide arch, the face and soffit of which were richly decorated with mosaics. Over the crown of the arch we often find a bust of Christ or the holy lamb lying upon the altar, and, on either side, the evangelistic symbols, the seven candlesticks and the twenty-four elders. Another arch spanned the semicircular apse, in which the church always terminated. From Carolingian times this was designated the arch of triumph, because a cross was suspended from it.
The conch or semi-dome that covered the apse was always covered with mosaic pictures, usually paintings of our Lord, either seated or standing, with St Peter and St Paul, and other apostles and saints, on either hand. The beams of the roof were sometimes concealed by a flat ceiling, richly carved and gilt. The altar, standing in the centre of the chord of the apse on a raised platform reached by flights of steps, was rendered conspicuous by a lofty canopy supported by marble pillars (ciborium, baldacchino), from which depended curtains of the richest materials. Beneath the altar was the confessio, a subterranean chapel, containing the body of the patron saint, and relics of other holy persons. This was approached by descending flights of steps from the nave or aisles. The confessio in some cases reproduced the original place of interment of the patron saint, either in a catacomb-chapel or in an ordinary grave, and thus formed the sacred nucleus round which the church arose. We have good examples of this arrangement at St Peter's and St Paul's at Rome, and S. Apollinare in Classe, Ravenna. It was copied in the original cathedral of Canterbury. The bishop or officiating presbyter advanced from his seat in the centre of the semicircle of the apse to the altar, and celebrated the Eucharist with his face to the congregation below. At the foot of the altar steps a raised platform, occupying the upper portion of the nave, formed a choir for the singers, readers and other inferior clergy. This oblong space was separated from the aisles and from the western portion of the nave by low marble walls or railings (cancelli). From these walls projected ambones or pulpits with desks, also of marble, ascended by steps.
The exterior of the basilicas was usually of an extreme plainness. The vast brick walls were unrelieved by ornament, save occasionally by arcading as at S. Apollinare in Classe, Ravenna, and had no compensating grace of outline or beauty of proportion. An exception was made for the entrance front, which was sometimes covered with plates of marble mosaics or painted stucco (Old St Peter's, S. Lorenzo). But in spite of any decorations the external effect of a basilica must always have been heavy and unattractive. S. Apollinare in Classe at Ravenna (fig. 8) affords a typical
example. The campanile is a later addition. Within, apart from the beautiful mosaic decoration, a fine effect was produced by the arch of triumph and the apse, which terminated the nave and dominated the whole vast space of the interior.
Fig. 10.—Ground-Plan of the original Basilica of St Peter's at Rome.