He was a grandson of John D'Arcy of Hydepark, County Westmeath, and a descendant of The 1st Baron Darcy de Knayth, one of the knights who had fought at the Battle of Crecy (1346).[3] In August 1919, D'Arcy was appointed Archbishop of Dublin, Bishop of Glendalough and Kildare and Primate of Ireland.[7] In 1921 he was appointed a member of the Senate of Southern Ireland, which was abolished with the establishment of the Irish Free State in 1922, but did not attend.[10] In 1934 he published his autobiography, The Adventures of a Bishop: a Phase in Irish Life, and in June 1937 announced that he intended to retire because of poor health.[2] Their son, John Conyers D'Arcy, Royal Artillery, fought in both World Wars and ended his career as the Commander of British forces in Palestine and Transjordan.