This eastern part of the church beyond the third bay from the tower was built in the latter half of the thirteenth century under the rule of Abbot John de Hertford, and completed by Abbot Roger Norton (1260-1290). The Lady Chapel was mainly built under the rule of Abbot Hugh de Eversden (1308-1326), one Reginald of St. Albans being the master-mason. It is in the Decorated style, and was begun as early as 1280. Abbot Wheathampstead (1420-1464) embellished it with much decoration in the Perpendicular style. It was with the ambulatory long separated from the church by a wall, and used as a Grammar School. A public path passed through the building here. The north side of the chapel and presbytery resembles the south. The north door is much later. The most western part of the wall is Norman. The north transept is entirely Norman, the work of Abbot Paul. On the east side were two apsidal chapels, removed in the fifteenth century. The upper part of the north front was rebuilt by Lord Grimthorpe. The north side of the nave preserves its Norman character, both in the clerestory and aisle, except at the west end, where it has been reconstructed in the Early English style. On the west of the Abbey is the _Great Gateway_, which is an unusually important building. The greater part of the present structure was built by Abbot Thomas de la Mare (1349-1396), but there seems to be some thirteenth century incorporated with it. Here the abbot held his court, and dealt out justice to the townsfolk and received his rents, and transacted other business; and here there were prisons for rebellious clerks and others. The gateway was stormed by Wat Tyler's rebels in 1381, who broke into the Abbey and terribly frightened the abbot and his monks. But vengeance was in store for the rioters, several of whom were imprisoned here and afterward hanged. After the dissolution it was used as the Assize Court, and subsequently as a prison. Then the Grammar School, evicted from the Lady Chapel, found a home here. All the other monastic buildings have been destroyed. THE INTERIOR