BUTT, ISAAC (1813-1879), Irish lawyer and Nationalist leader, was born at Glenfin, Donegal, in 1813, his father being rector of Stranorlar. He was a brilliant student at Trinity col lege, Dublin, where he helped to found the University Magazine in 1833, and where he was appointed professor of political economy in 1836. Called to the Irish bar in 1838, he was made a Q.C. in 1844, and took part in all the important Irish law cases of the time, being engaged in the defence of Smith O'Brien in 1848, and of the Fenians between 1865 and 186q. He began by taking an active part in politics as a Conservative, was a defend er of the old corporation, and of Protestantism, and started the Protestant Guardian, which later became part of the Orange Warder; in 184o he was chosen to defend the old corporation of Dublin before the bar of the House of Lords. Butt was also a warm supporter of the union. In 1852 he was returned to parlia ment by Youghal as a Liberal-Conservative, and retained this seat till 1865. During his parliamentary career he drifted away from conservatism, and by when he returned to Ireland, he was definitely Liberal. Disappointment at the disestablish ment of the Irish church drove Butt with other Irish Protestants into union with the Nationalists, and as leader of this coalition he evolved the federal theory of Home Rule. At a large meeting on May 19, 187o, in Dublin he inaugurated the Home Rule movement, and after his election in 1871, for Limerick, he found himself at the head of a party of 57 members. The Home Rule league was founded in 1872, but gradually the Protestant and Conservative members dropped out ; Butt himself disapproved of violent methods and obstruction in parliament, and remained convinced that the union between Ireland and England must stand. The party got beyond his control, and extremists accused him of being a political traitor, his false position assisted in breaking down his health, and he died in Dublin, on May 5, 1879.