Abbot Hugh of Eversden began to rebuild this ruined part of the church, and this accounts for the five bays of the nave arcading westward of the rood-screen being in fourteenth-century style. He did not live to finish all this work, but it was carried on by his successor, Richard of Wallingford (1326-1335), and finished by the next Abbot, Michael of Mentmore, about 1345. The present rood-screen, which probably took the place of a previously existing one of Norman date, was built in 1360 by Thomas de la Mare. No further change of importance was made until the time of John of Wheathampstead, who was Abbot from 1420 to 1440, and again from 1451 to 1464. He left his marks in various parts of the Abbey, and for the most part his work was bad: he did almost as much to injure the Abbey as the nineteenth-century restorers who swept away much of his work have done. He rebuilt all the upper part of the west front, and inserted Perpendicular windows at each end of the transept; he turned the high-pitched roofs of nave and transepts into flat ones, and lowered the slope of the roofs of the aisles. His object in doing this was to be able to use the old beams again whose ends were decayed, and which were shortened by cutting off the unsound parts. The result of this was that the Norman triforium arches on the north side were thrown open to the sky; these he filled with Perpendicular tracery, converting them into windows. The tracery still remains, although the new roof has the same slope as the original one, and the triforium is now again inclosed beneath it. He also pulled down the wooden octagon on the central tower. His chantry on the south side of the high altar was probably erected soon after his death. Abbot William of Wallingford (1476-1484) built the high altar screen, carrying out a plan which John of Wheathampstead had not been able to accomplish. The only addition made after this to the Abbey is the chantry of Thomas Ramryge, who became Abbot in 1492. The exact date of its construction is not known, all records of the Abbey during Ramryge's rule having perished; but from its style it is generally supposed to have been built about the year 1520. During the reign of Henry VIII. all the monasteries were dissolved; first the smaller, then the more important ones, among them that of St. Albans. The fortieth and last Abbot of St. Albans, Richard Boreman of Stevenage, surrendered the Abbey on December 5th, 1539, he and the monks receiving pensions as compensation. [Illustration: EXTERIOR OF LADY CHAPEL WHEN USED AS THE GRAMMAR SCHOOL BEFORE 1874. (From the Official Guide to the Great Northern Railway.)]