The earliest extended development of the eastern end of the cathedral is that which was first set out in Edward the Confessor's church at Westminster, probably borrowed from the ancient church of St Martin at Tours; in this church, dating probably back to the 10th century, two new elements are found:

The carry of the choir aisle round a circular apse so as to provide an occasional aisle round the eastern end of the church
Five apsidal chapels, constituting the germ of the chevet, which formed the eastern terminations of the French cathedrals of the 12th and 13th centuries.
Gloucester (1089) also had three chapels, two of which, on the north and south sides of the aisle, still remain; the same is found in Canterbury (1096-1107) and Norwich (1089-1119), the stern chapel in all three cases having been taken down to make way for the Lady-chapel in Gloucester and Norwich, and the Trinity chapel in Canterbury cathedral.

The semicircular aisle is said to have existed in the Anglo-Norman cathedral of Winchester, but the eastern end being square, two chapels were arranged filling the north and south ends, and an apsidal chapel projecting beyond the east wall. This semicircular processional aisle with chevet chapels was the favourite plan in the Anglo-Norman cathedrals, and was followed until about the middle of the 12th century, when the English builders in some cases returned to the square east end instead of semicircular apsidal termination. The earliest example of this exists in Romsey Abbey (c, 1130), where the processional crosses behind the presbytery, there being eastern apsidal chapels in the axis of the presbytery aisle and a central rectangular chapel beyond.

A similar arrangement is found in Hereford cathedral, and exists in Winchester, Salisbury, Durham, Albans, Exeter, Ely, Wells and Peterborough, except that in those cases (except Wells) the eastern chapels are square; in Wells cathedral the most eastern chapel (the Lady Chapel) has a polygonal termination; in Durham, the chapels are all in one line, constituting the chapel of the altars, which was probably borrowed from the eastern end of Fountains Abbey.

rebuilding; thus in Albans, Durham, York and Exeter cathedrals, there was no ambulatory but three parallel apses, in some cases rectangular externally. In Southwell, Rochester and Ely, there was no processional path or ambulatory round the end; in Carlisle no eastern chapels; and in Oxford only one central apse.

In Ely cathedral the great central tower built by the first Norman abbot (1082-1094) fell down in 1321, taking with it portions of the adjoining bays of the nave, transept and choir. Instead of attempting to rebuild the tower, Alan of Walsingham conceived the idea of obtaining a much larger area in the centre of the cathedral, and instead of rebuilding the piers of the tower he took as the base of his design a central octagonal space, the width of which was equal to that of nave and aisles, with wide arches to nave, transepts and choir, and smaller arches across the octagonal sides; from shafts in the eight pier angles, ribs in wood project forward and carry a smaller octagon on which the lantern rests. Internally the effect of this central octagon is of great beauty and originality, and it is the only instance of such a feature in English Gothic architecture.