The “Black Castle” is therefore no doubt the fortress alluded to in an inquisition held in September, 1612, which states that Gerald FitzGerald, son of Gerald, late Earl of Kildare, and uncle of Gerald, late Earl of Kildare, was seized of one castle, three messuages, one ruined water-mill, and forty acres of arable land at Leixlip. And again in 1621 the inquisition taken upon the death of Gerald, 15th Earl of Kildare, includes the Castle of Leixlip, &c. While the rental of the Earl of Kildare in 1657 mentions the black castle of Leixlip with sixty acres of land valued at £15 a year. Leixlip Castle was purchased by the Right Hon. William Conolly, Speaker of the Irish House of Commons, at the beginning of the eighteenth century. He subsequently built the mansion of Castletown at Celbridge, but his nephew and heir occupied Leixlip Castle during the famine years of 1740 and 1741. After this period the castle has been inhabited by many distinguished tenants. It was a favourite residence of Primate Stone, and during Lord Townshend’s period of office he usually passed the summer there. Many stories are told of this Viceroy’s fancy for mixing incognito with “all sorts and conditions of men.” One day Lord Townshend met a journeyman cutler named Edward Bentley in the demesne of Leixlip Castle and began to talk to him. Bentley was loud in his praises of the Lord Lieutenant’s kindness in allowing the public into the grounds of his residence, but he was equally vehement in denouncing the political views he held. Mistaking the proprietor for one of the retainers, he offered him half a crown upon leaving, and when it was refused the cutler commented on the difference between his action and that of the gate-keeper who had demanded that amount. Lord Townshend then took him to the castle and provided him with a cold repast, but as he was escorting his departing and grateful visitor through the hall the unfortunate gate-keeper came in. The Lord Lieutenant asked him why he had dared to disobey orders and receive money from visitors. Whereupon the man fell upon his knees and asked pardon. Bentley, at last realising who had been his entertainer, immediately followed suit. Lord Townshend sent for his sword, and the cutler was quite certain that his last hour had come. The Lord Lieutenant flourished the weapon over his head and brought it down smartly on the terror-stricken man’s shoulder, saying, “Rise, Sir Edward Bentley.” The new-made knight was appointed cutler to His Excellency, and lived long to enjoy his honour. Viscount Townshend’s wife died at Leixlip Castle. The Hon. George Cavendish remodelled the building and brought it up to modern requirements during his tenancy before 1837. John Michael, Baron de Robuck, subsequently lived there, and was drowned in the Liffey in 1856 during a flood. In 1878, Captain the Honourable Cornwallis Maude, son of the Earl of Montalt, took the castle after his marriage. He was killed at Majuba Hill.