Butt, Isaac, politician, was born in 1813 in Donegal county. Called to the bar in 1838, he acquired a great reputation as a lawyer, receiving the silk gown in 1844. In 1852 he entered Parliament, as a Conservative, as member for Youghal, which constituency he represented till 1865. Meanwhile his political views were undergoing a change, and in 1871, when he was returned for Limerick, he became leader of the Home Rule party. In 1872 the Home Rule League was formed, only, however, to die through internal dissensions. Butt himself, being too moderate to satisfy the extreme portion of his following, was denounced, and lost hold of the party altogether. He died in 1879 near Dundrum, in county Dublin.