The Conqueror, before he entered London, formed a camp, eastward of the city, and probably on part of the ground now occupied by the Tower. Immediately after his coronation he commenced the works here. At first, no doubt, they consisted of a ditch and palisade, and were formed partly on the lower bastions of the old City Wall, first built by the Romans, and rebuilt in 885 by King Alfred. The work of building the Keep was entrusted to Gundulf, a monk of Bec, in Normandy, who was shortly afterwards made Bishop of Rochester, and who probably commenced operations in 1078. In 1097, under William Rufus, the works were still going on and the inner ward was enclosed. A great storm in 1091 damaged the outworks. Ralf Flambard, Bishop of Durham, being imprisoned in the Tower by Henry I, contrived to escape, 1101. During the wars between Stephen and Matilda, the Earl of Essex was Constable of the Tower, and obtained a grant even of the City of London from the Empress. When he fell into Stephen's hands the Tower formed his ransom, and the citizens regained their ancient liberty. When Richard I was absent on the Crusade, his regent, Longchamp, resided in the Tower, of which he greatly enlarged the precincts by trespasses on the land of the city and of St. Katharine's Hospital. He surrendered the Tower to the citizens, led by John, in 1191. The church of St. Peter was in existence before 1210, and the whole Tower was held in pledge for the completion of Magna Charta in 1215 and 1216. In 1240 Henry III had the chapel of St. John decorated with painting and stained glass, and the royal apartments in the Keep were whitewashed, as well as the whole exterior. In the reign of Edward III it begins to assume its modern name, as "La Blanche Tour." During the wars with France many illustrious prisoners were lodged here, as David, King of Scots; John, King of France; Charles of Blois, and John de Vienne, governor of Calais, and his twelve brave burgesses. In the Tower Richard II signed his abdication, 1399. The Duke of Orleans, taken at Agincourt, was lodged by Henry V in the White Tower. From that time the Beauchamp Tower was more used as a prison, but it is probable that some of the Kentish rebels, taken with Wyatt in 1554, slept in the recesses of the crypt of the Chapel, long known as Queen Elizabeth's Armoury. In 1663, and later years down to 1709, structural repairs were carried out under the superintendence of Sir Christopher Wren, who replaced the Norman window openings with others of a classical character. Remains of four old windows are visible on the river side. A few years ago some disfiguring annexes and sheds were removed, as well as an external staircase of wood, which led up from the old Horse Armoury and entered the crypt by a window.