The next step appears first in ninth century churches, and in the plan of the monastery of St Gall. It involved no change in the position of the stalls of the clergy; but instead of being placed in the eastern bays of the nave, the sanctuary was lengthened to contain them. And so we reach the familiar parochial chancel, with its western portion forming a choir, and its eastern a sanctuary. The clergy left the nave and the laity in the midst of whom they had so long sung and prayed, and removed to the chancel, where to the north and south were solid walls, while to the west, no doubt very shortly, was added a screen guarding the entrance to the chapel. Though the new plan made no alteration in the relative position of the stalls of the clergy, it was nevertheless a real revolution. The chancel became practically a secluded, closed chapel; the offices and services which had been performed in the midst of the laity became more and more the prerogative of a privileged ecclesiastical order; in the end, in the greater churches, special altars were put up for the laity in the nave; except in the parish churches, laymen lost the right to participate in services at the High Altar.
Carlisle
In our great monastic and collegiate churches it was long before the ninth century innovation—viz., the insertion of the choir in the eastern limb of the church—was generally adopted; in some it was never adopted at all. The typical Cistercian churches, e.g., Kirkstall, reverted to the Early Christian arrangement, by which the eastern division of the church was appropriated exclusively to the sanctuary; and this was the case with many Benedictine and collegiate churches also. Till ignorant and incompetent "restorers" were let loose on them, the eastern limb of the cathedrals of the Secular Canons of Wells and Hereford, that of the Benedictine cathedral of Ely and others formed one vast sanctuary, the stalls being placed under the central tower and in the eastern part of the nave; at Wells the choir had a length of 47 feet, but the sanctuary of 67 feet. The reason why a sanctuary so long was required was no doubt that it was desired to place in it two altars; one, the "choir" or "matins" altar, for ordinary services; the other, the High altar, more to the east, reserved for High Mass.[[8]]
Durham
In some cases, e.g., at Westminster, in many Cistercian churches, and in Spanish cathedrals, the stalls were not placed under the central tower, but still more to the west, wholly in the nave. In Gothic days, however, in English plans—Westminster is French in plan—the tendency was more and more to place the choir of the monastic and collegiate churches in the eastern limb, just as in a parish church. In the cathedrals the precedent was first set at Canterbury, where in 1096 Prior Ernulph set out a new eastern limb consisting of an eastern apse preceded by no less than nine bays. Sometimes there was a special reason for the removal of the choir from the crossing and the nave. In several cases—in pious recollection of the burial of many a martyr in Early Christian days down in the catacombs of Rome—the Italian practice of constructing a crypt beneath the eastern limb was followed. This had been so as early as St Wilfrid, 671-678, whose crypts at Ripon and Hexham still survive, and in the Anglo-Saxon cathedrals of Winchester, Worcester, Rochester, Gloucester, Canterbury, York, and Old St Paul's. And when these were remodelled by the Norman conquerors, in all cases the crypt was reproduced. Such crypts of course necessitate the building of the eastern limb at a higher level than crossing and nave; in some cases, e.g., at Canterbury, the difference in height is very considerable. The result must have been that where as at Canterbury the sanctuary was a long one, the High altar at its east end must have been invisible, or nearly so, to monks seated in the crossing and nave. Consequently, first at Canterbury c. 1100, in the thirteenth century at Rochester, Old St Paul's and Worcester, and in the fourteenth century at Winchester and York, the stalls were removed to the eastern limb, the western portion of which now became choir. The only exception among cathedrals with crypts is Gloucester, where the crypt is low and the eastern limb is short and where the stalls remain to this day beneath the central tower. The example set by cathedrals with crypts was soon followed by churches of every degree which had none; whether Benedictine, such as at Chester, Augustinian, as at Carlisle, or served by Secular Canons, as at Exeter. And so in the churches of monks, regular canons and secular canons alike, most of the ecclesiastical authorities reverted to what had been all along the normal plan of the English parish church, viz., an eastern limb containing choir as well as presbytery.[[9]]