O'Brien, William Smith, born in 1803, was educated at Harrow and Cambridge, entered the House of Commons for Ennis in 1826. and sat for county Limerick from 1835 to 1848. Except as to the removal of the Catholic Disabilities, he did not at first sympathise with O'Connell, but after the Arms Act of 1843 he joined the Young Ireland party, and in 1847 started the Irish Confederation. He was arrested and tried for sedition in 1848, but not convicted. In July he started his "War Directory," and began actual hostilities at Ballingarry. A few troops soon dispersed his followers, and, being again tried, he was condemned to death, a sentence afterwards commuted to transportation for life. But in 1854 he was released, and fully pardoned in 1856, dying at Bangor, North Wales, in 1864.