FitzStephen, in the reign of Henry the Second, describes the “Arx Palatina” as being then, “great and strong with encircling walls rising from a deep foundation, and built with mortar tempered with the blood of beasts.” Probably the sanguinary aspect of the mortar used in the Tower buildings was owing to the use of pulverised Roman red tiles and bricks, of which a large quantity were most likely pounded into mortar. When Richard Cœur de Lion left England for the Holy Land he entrusted the charge of guarding the Tower to Longchamp, Bishop of Ely, who was his Chancellor. This Bishop strengthened the fortress and deepened the moat. He had good reason for his work upon the fortress, for John, taking advantage of his brother’s absence, besieged the Tower; but the Bishop, thinking discretion the better part of valour, yielded up his trust without attempting to defend it, and fled for safety to Dover Castle. John made over the Tower to the confederated nobles under the Archbishop of Rouen, who occupied it until Richard’s return from the Holy Land. In 1215, the Barons, who were then up in arms, aided by the London citizens, besieged the Tower, but although it was poorly garrisoned, their attacks were repelled. A year later, whilst the civil war was waging between John and his barons, the Tower was handed over to the French prince Louis by the rebellious nobles, who had invited him to take John’s place as King of England, but Louis does not seem to have taken kindly to the position, and speedily returned to his own land. In 1217, Henry III. was reigning in undisputed possession of the realm, and to him belongs the credit of having done more towards making the Tower worthy of a royal abode, than any of his predecessors or successors upon the English throne. The most stately of its buildings, after the Great Keep, are due to his love of art and architecture. The Royal Chapel, the Great Hall, and the Palace chambers, which he either built or decorated, are frequently mentioned in the chronicles of Henry’s reign, and were the outcome of his taste and love of magnificence. In 1232 the Tower was given into the custody for life to the famous Hubert de Burgh, Earl of Kent. His constableship, however, was brief, he being supplanted by Peter de Roches, Bishop of Winchester, and imprisoned in the fortress he had formerly governed.