§ 31. The eastern arm of a Benedictine church was normally aisled. In the common plan of a Norman abbey church the presbytery ended in an apse, which contained the high altar, standing clear of the eastern wall, and projected a bay east of the ends of the aisles, which were internally apsidal but externally were finished off square. This plan was followed in Lanfranc's church at Canterbury, at Durham, Peterborough, Westminster and elsewhere, and was not confined to monastic churches. In England, however, a plan was sometimes followed which was unusual in Normandy, although it is common in Romanesque churches in other parts of France. The aisles in this case were continued round the apse, so as to form a processional path behind the altar; and out of this path opened three apsidal chapels, as at Gloucester and Norwich, or five, as in the Cluniac church of Lewes, where the plan was borrowed from the parent church of Cluny. This plan was of great convenience for processions and afforded room for at least one additional altar. It was adopted in the abbey church of St Augustine at Canterbury, and in the rebuilding of the eastern arm of the neighbouring cathedral priory. Gloucester, Norwich and Tewkesbury are examples of its use in Benedictine churches; and it occurs in the Augustinian priory church of St Bartholomew, Smithfield. In these cases the processional path was retained through all later alterations, and the original arrangement is still quite clear; while the alternative and at one time more common plan has generally disappeared in England, and Peterborough is the one large church in which there are substantial remains of it above the foundations. Although the influence of Cluny upon foreign Romanesque architecture was considerable, the English Cluniac churches had no distinct plan of their own. Castle Acre, for example, followed the ordinary Norman plan as seen at Durham and Peterborough; and later developments at Castle Acre and Wenlock were carried out on models common to churches of other orders.