Butler, William Francis Thomas (1869–1930), educationist and historian, was born 22 December 1869 at Canal St., Newry, Co. Down, eldest among three sons and three daughters of Thomas Butler, resident magistrate, and Annie Butler (née Barry). A leasing dispute had forced the Butler family out of their family home in Ballyslateen, Co. Tipperary, the year before William's birth, and he spent his childhood in Newry, Co. Down, Kilkee, Co. Clare, and Mallow, Co. Cork, where his father served as an RM. He graduated MA from the Royal University of Ireland in 1894 and the following year took up a post as professor of modern languages at QCC, where he remained till 1910, serving also as college registrar (1906–10). He was appointed assistant commissioner of the intermediate board of education in 1910, and on its dissolution he became principal officer of the secondary branch of the Department of Education.
A historian, genealogist, and antiquarian, he published numerous articles in contemporary periodicals and was a pioneering authority on land ownership and tenurial rights in early modern Ireland. His principal publications include The Lombard communes; a history of the republics of north Italy (1906), Confiscation in Irish history (1917), and Gleanings from Irish history (1925). He was a member of the NUI senate, the RIA, and the IMC, and served (1928–9) as president of the RSAI.
Butler was a nephew of Gen. Sir William Francis Butler (qv), husband of the painter Elizabeth Southerden Thompson (Lady Butler; qv); his brother Sir Edwin John Butler (qv) was a noted botanist. He was unmarried and lived at Hume St., Dublin, for many years. He died in Dublin 13 February 1930.