There seems no doubt that this chapel was originally a Norman apse with a vaulted chamber[15] above, like that in the sister transept, and that it was enlarged in the thirteenth century by Prior Henry Sipton. This is distinctly stated in Annals to have been done in the case of the chapel dedicated to St. Nicholas in 1237. No trace remains of any of the work of Prior Sipton owing to the later works carried out in this chapel. The nave of a Lady Chapel was built on the north side of the north transept, and its chancel (the existing northern part of the choir vestry) was carried out to the east, this portion of the chapel being quite detached, as the windows (now blocked up) in the upper part of the south wall plainly show. Access for the laity was given by a door in the nave portion, while the monks had an entrance through the adjoining chapel, which may, after its rebuilding in 1237, have contained two altars, one to St. James and another to St. Nicholas. This theory of the two altars in this chapel would account for much of the confusion in the naming of the chapel by subsequent writers. The vaulting of this chapel is at first sight a difficult problem to solve, as the eastern side is divided into two equal parts, while the western side is divided into two unequal parts. A pillar seems to have stood in the centre, if the lists of noblemen buried (after the battle in 1471) in the two chapels are trustworthy. When the fourteenth century Lady Chapel at the east end of the church was built, the _raison d'être_ of the Early English Lady Chapel ceased, and the chapel entrances were enlarged to their present form. Any distinctive features that they had in the way of wall decoration were lost either at the Dissolution, when part was pulled down, or during the subsequent use of the eastern chapels as a schoolroom. Passing through into the adjoining chapel on the north, which was probably the chancel of an =Early English Lady Chapel=, the visitor will note the great contrast between this and the adjacent chapel. It is very much richer in its ornament, and though it has been terribly mutilated, much work of surpassing interest is still left to us. The north wall contains the remains of a trefoil-headed arcade of great beauty, the spandrils of which show richly carved foliage, the effect of which was further heightened by the application of colour. Of the arcading eleven capitals remain, but only three pillars and bases, the rest having been cleared away. [Illustration: (_H.J.L.J.M._) WALL ARCADE IN EARLY ENGLISH CHAPEL.] In the wall of the present west end is a window decorated with a moulding consisting of two series of chevrons, completely undercut, pointing laterally in contrary directions.[16] Numerous interesting remains of Early English mason's work are in the chapel, and many have been built into the wall on the east side, the most important being remains of a fine altar-piece in Purbeck marble.