The twelfth-century church was very remarkable in plan. Not only had it an aisled nave and an aisled choir, but it had the architectural luxury, unparalleled in our Norman architecture except in the vast churches of Winchester and Ely, of eastern and western aisles to its transepts. The site, however, was cramped to the south, and so the southern transept was shorter than the northern one; moreover, this short transept later on lost its west aisle, which was lopped off to allow the cloister to be extended. For the same reason—lack of room—the slype, or vaulted passage, which in all monastic institutions connected the cloister with the cemetery, instead of being built between the transept and the cloister, was built inside the church, as at Hexham, curtailing still further the floor area of the north transept. It was therefore because the church was so cramped to the south, that the other transept was given aisles on both sides. Instead of an eastern aisle, the south transept had merely a square chapel projecting eastward. But the canons wanted also a Lady chapel, for the church seems to have been dedicated originally to the Holy Trinity, St. Mary and St. Frideswide. The normal position of a Lady chapel was to the east of the sanctuary. But here also the canons were cramped; for quite close to the east end of the church ran the city wall. To get in a Lady chapel, therefore, they had to build an additional aisle north of the north aisle of the choir. This was three bays long. It was probably walled off from the transept, but opened into the north choir-aisle by three Norman arches, reconstructed later on. The same arrangement is found at Ripon. There was also a short chapel projecting eastward from the northernmost bay of the east aisle of the north transept. The east end, as at Rochester and Ripon, was square. The present east end is a fine composition by Scott, more or less conjectural. The work commenced, as usual, at the east, as is shown by the gradual improvement westward in the design of the capitals. The evidence of the vaulting, too, points in the same direction. In the choir-aisle the ribs are massive and heavy; in the western aisle of the north transept they are lighter; in the south aisle of the nave they are pointed and filleted. The transepts are narrower than the nave and choir; the tower, therefore, is oblong, and, as at Bolton Priory, its narrow sides have pointed arches: semicircular arches would have been too low. The faces of the piers of the towers are flat, because the stalls of the canons were placed against them and in the eastern bays of the nave, leaving the whole eastern limb as sanctuary.