The space in the church for the high altar and the clergy. It is variously designated apsis or concha (from the shell-like, hemispherical dome), and since the Middle Ages especially it has been called "choir", from the choir of singers who are here stationed. Other names are presbyterium, concessus chori, tribuna or tribunal, hagion, hasyton, sanctum, sanctuarium.

From the architectural standpoint the sanctuary has undergone manifold alterations. In Christian antiquity it was confined to the apse, into the wall of which the stone benches for the clergy were let after the fashion of an amphitheatre, while in the middle rose up the bishop's chair ( cathedra). It would however be wrong to believe that this ancient Christian sanctuary had always a semicircular formation, since recent investigations (especially in the East) have revealed very various shapes. Over a dozen different shapes have already been discovered. In Syria the semicircular development advances very little or not at all from the outer wall, while beside it are situated two rooms which serve respectively for the offering ( prothesis) and for the clergy ( diaconicum). The sanctuary was often formed by three interconnected apses ( Dreiconchensystem); the quite straight termination also occurs. An important difference between the Roman and Oriental churches consisted in the fact that in the case of the latter the wall of the sanctuary was interrupted by a window through which the sunlight freely entered, while the windowless Roman apse was shrouded. in a mysterious darkness.

As the semicircular niche could no longer in all cases hold the numbers of the higher and Lower clergy, a portion of the middle nave was often enclosed with rails and added to the sanctuary, as may be seen today in the San Clemente at Rome. Outside Rome this necessity of enlarging the sanctuary was met in another way, by introducing between the longitudinal (or cross) aisle and the apse a compartment or square, the basilica thus receiving (instead of the Roman T-shape) the form of a cross. This innovation was of far-reaching importance, since the sanctuary could not develop freely. This development proceeded from the beginning to the close of the Middle Ages in what may be declared as an almost wanton fashion. The time at which this innovation was introduced has been for a long time the subject of a violent literary feud, since it is most intimately connected with the development of the cruciform arrangement of churches. Some investigators hold that this form is first found in the Monastery of Fulda under Abbot Bangulf about the year 800; according to others it occurred before the time of Charlemagne in the French monasteries of Jumièges and Rebais. In recent times Strzygowski has maintained that both views are incorrect, and that the extended sanctuary, or in other words the cruciform church, was already common in the early Christian period in Asia Minor, and was thence transplanted to the West by Basilian monks as early as the fourth or fifth century.

A second very important alteration, which occurred during the Carlovingian Renaissance, consisted in the introduction or rather transplantation from the East to the West of the "double sanctuary". By this is meant the construction of a second sanctuary or west choir opposite the east; this arrangement was found even in ancient times in isolated instances, but its introduction in the case of larger churches gradually became universal in the West. Concerning the reasons for this innovation various theories have been put forward. It must, however, be recognized that the reasons were not everywhere the same. They were three in particular: the duplication of the titular saints, the construction of a place for the remains of a saint, and the need of a nuns' or winter choir. In addition, Strzygowski has also maintained the influence exercised by the change of "orientation", that is the erection of the altar, which in the East originally stood in the west of the church, at the eastern end. The second reason seems to have given incentive most frequently to the construction of the second choir. Thus in 819 Abbot Ansger built a west choir with a crypt to receive the remains of St. Boniface; in Mittelzell (Richenau) this choir was constructed for the relics of St. Mark, in Eichstatt (1060) for the remains of St. Willibald. Especially suitable for nuns' convents was the west choir with a gallery, since from it the nuns could follow Divine Service unobserved; for this reason the church built at Essen (Prussia) in 874 received a west choir in 947.

The increase of the clergy, in conjunction with the striving (in the Romanesque period) after as large crypts as possible, led to the repeated increase of the sanctuary, which, however, exercised a very prejudicial influence on the architectural arrangement of space. The sanctuary was extended especially westwards - thus into the longitudinal aisle, but at times also into the cross aisle. Examples of this excessively great extension are supplied by the cathedrals of Paderborn and Speyer. The walls of this sanctuary, which had thus become a formal enclosure, were often decorated with Biblical reliefs; here, in fact, are preserved some very important Romanesque reliefs, as on the Georgentor at Bamberg and in the Church of St. Michael at Hildesheim. But even in the Romanesque period began the war against this elevated sanctuary, waged mainly by the monks of Hirsan (Germany), then highly influential, and the Cistercians. The former as opponents of the crypts, restored the sanctuary to the same level as the nave or made it only a few steps higher; they also ended the sanctuary in a straight line, and gave it only a small round apse. More important was the change made by the Cistercians, who, to enable so many priests to read Mass simultaneously, resolved the eastern portion into a number of chapels standing in a straight line at either side of the sanctuary. This alteration began in the mother-house of Cisteaux, and extended with the monks everywhere even to the East.

These alterations paved the way for the third great transformation of the sanctuary: this was accomplished by Gothic architecture, which, in consequence of the improved vaulting, found it easier to conduct the side aisles around the choir, as the Romanesque architects had already done in individual cases. The sanctuary indeed was not thereby essentially altered, but it was now accessible on all sides, and the faithful could attain to the immediate vicinity of the high altar, When it was not separated by a wall, an entirely free view of the sanctuary was offered. For the most part, however, the termination of the sanctuary with walls was retained, while in front was still erected the screen, which enjoyed in the Gothic period its special vogue. This arrangement of the sanctuary is usually found in the great cathedrals after the French models, and may thus be designated the "cathedral type", although it also occurs in the larger parish and monastery churches. Frequently the sanctuary has an exceptional length; this is especially the case in England, and influenced the architectonic arrangement of space if the sanctuary was enclosed with walls. Its effect was most unfavourable in the canon's choir (called the Trascoro) in the cathedrals of Spain, which was transferred to the middle nave as a separate construction and was cut off by high walls with grated entrances. This enclosure was most magnificently decorated with architectural and other ornamentations, but it entirely destroyed the view of the glorious architecture. Side by side with this "cathedral type" was retained the old simple type, in which the sanctuary was not accessible on all sides; this was found especially in parish churches and in the churches of the mendicant orders. When the church had three naves, the choirs of the side naves lay beside the chief choir. This kind of a sanctuary remained the most popular, especially in Germany and Italy.

The Renaissance to a great extent restored to the sanctuary its original form. In the effort to increase the middle nave as much as possible, Renaissance architecture in many cases neglected the side naves or limited them to the narrowest aisles. The free approach to the sanctuary from all sides thus lost its justification. The sanctuary necessarily received a great breadth, but lost its earlier depth. In its preference for bright and airy spaces, the Renaissance also abandoned the method of separating the sanctuary from the rest of the church by means of a screen; at a subsequent period, the latter was replaced by the low Communion bench. Thus a person entering the church through the main door commanded a free view of the sanctuary, which, especially in Italy, was gloriously decorated with marble incrustations. As the sunlight, entering unchecked through the cupola covering the intersection, brightly illuminated the edifice, the effect was entirely different from that awakened by the Romanesque and Gothic sanctuaries. In the medieval church the sanctuary was shut off from the congregation and was as inaccessible as the Holy of Holies in the Temple of the Old Testament; the sanctuary of the Renaissance church stands out before us in a brilliance of light like Mount Tabor, but without blinding our gaze. We believe that we are nearer the Deity, our hearts are filled with joyous sentiments, so that we might cry out with the Apostle Peter "It is good for us to be here". In the medieval church, on the other hand, we are penetrated with a mysterious awe and like Moses feel urged to take off our shoes, for this is a holy place.

STRZYGOWSKI, Kleinasien. Ein Neuland der Kunstgeschichte (Leipzig, 1903); HASAK, Die romanische u. gotische Baukunst der Kirchenbau (Stuttgart 1902).

Beda Kleinschmidt.