The Butlers sold Kilkenny Castle to the town for £50 in 1967, and the Ormonde earldoms went dormant in 1997

The Butlers, Earls and later Marquesses of Ormonde, kept a collection of about 500 paintings at Kilkenny Castle, the largest in Ireland. In 1922, during the Irish Civil War, Republicans were besieged in the castle by Free State forces. George Butler, Earl of Ossory, and his family had lived there since 1921. In 1935 they left. The contents were sold at a ten-day auction for £6,000, and the family moved to London. The castle stood empty for thirty years. In 1967 Arthur Butler, 6th Marquess, sold it to the Kilkenny Castle Restoration Committee for £50 and handed the key to its chairman, James Gibbons. He also bought the land in front so it could never be built on. The Butler Society was founded at the handover. The Office of Public Works began repairs in 1969 and opened the castle to the public in 1976. The 6th Marquess died on 17 April 1971. The titles passed to his cousin Charles Butler, who had emigrated to the United States in 1928 and was business manager of the Art Institute of Chicago. Charles died in Chicago on 25 October 1997, aged 98. He had two daughters and no son. The marquessate became extinct and the earldoms of Ormond and Ossory became dormant. The Viscounts Mountgarret are the presumed heirs, but no claim has been submitted to the Crown. In 2026 the castle belongs to the people of Kilkenny and the Office of Public Works runs it.