APSE (Cr. ao's; Let. absis, tribuna, concha ; Fr. abside, chet'et, rond-point; Ital. upside, tribuna ; Ger. Ablaut), the semicircular or polygonal termination to a church. These forms were no doubt derived from the concha or bona, in the classic and early Christian basilica. In both cases it was the place appropriated to those who administered justice, the praetor's chair in the one being represented by the bishop's throne in the other. The altar stood not within the apse, but on the chord of its are. Sometimes the apse is a simple semicircle ; sometimes in large churches out of this a smaller semicircle springs, as Becket's Crown at Canterbury, and at Sens, Langres, and in many other churches abroad. Sometimes the choir finishes with three apses - one to the central aisle, and one to each side aisle, as at Autun. Sometimes the plan is a semicircle, each bay of which has a projecting semicircular apse, forming a sort of cluster of apses, as at Beauvais, Troyes, Tours, &c. The later choir at Mans is encircled by no less than thirteen apses, the centre one being twice the depth of the others, and forming the Lady-chapel. In some small churches of the Norman period, there is a sort of double chancel, one square, and the other an apse projecting eastward, each of which has its own arch, as at Sutton, East Ham, Darent, &c. Large circular and polygonal apses generally have radiating chapels within, as at Westminster Abbey. The earliest cathedral at Canterbury had an apse at each end, if we may trust the old plan ; and there are several instances of the same kind in France and Germany. Apses project from the north and south ends of the transepts, and from their east sides in a few cases abroad, the only example of this in England being at Norwich.