Of the eight towers which once protected the fortress only the Wardrobe Tower now remains, often erroneously called Birmingham Tower. This, as its name implies, is where the royal robe, cap of maintenance, and other furniture of state were kept. The sword of state is still preserved there, and also the records which were removed from Birmingham Tower. The lower portion is the original masonry, but an upper storey was added when the Chapel Royal was built. The Birmingham Tower was rendered unsafe by an explosion of gunpowder in Ship Street and had to be taken down. A lighter structure was erected on the site, which contains the present kitchen and viceregal supper-room. The other towers were gradually removed to make room for new buildings. The Anglo-Irish used to decorate the gate and walls of the castle with the heads of the slain, and in 1316 some four hundred heads were sent from Wicklow for this purpose. The castle did not become a permanent residence of the Viceroy until 1560 by order of Elizabeth, and in 1565 Henry Sydney took up his abode in it. He also enlarged and beautified it, and placed the State papers there in safe keeping. The castle has stood several successful sieges. In 1478 Gerald, 8th Earl of Kildare, was superseded as Lord Deputy by Lord Grey of Codnor. He refused to resign, and Keating, Prior of Kilmainham, and Constable of the Castle, sided with him, and fortified the stronghold against the new Deputy. He destroyed the drawbridge, and Lord Grey, finding his numbers too small to force an entrance, returned to England, and Kildare was shortly afterwards reinstated. Again, in 1534, young Lord Offaly, known as “Silken Thomas” from the splendour of his horses’ trappings, hearing a false report that his father had been treacherously executed in England, returned the Sword of State to the Council, which he held as Deputy in the Earl of Kildare’s absence, and commenced hostilities against the castle. It is said the citizens readily admitted him within the walls of Dublin. His chief attack was from Ship Street, but the Constable of the castle getting the thatched houses there set on fire, the besiegers fell back into Thomas Street. Lord Offaly having been obliged to commence hostilities against Ossary, the siege was not carried on with much heart. Many of the arrows sent into the castle were headless, and others bore letters saying some of the besiegers were really in sympathy with the King’s party. Upon the rumour of help from England, the citizens closed the gates and made prisoners of the attackers. Lord Thomas hurried back, and at once laid siege to the city itself, but his force was too small to have any effect. As he had seized the Dublin children who had been sent to outlying villages on account of the plague, the citizens agreed to liberate his party if the little ones were restored. This was done, and shortly afterwards aid from England quelled the rebellion.