William O' Brien, Patriot, was born in Dromoland, County Clare on October 17th, 1803. He was the second son of Sir Edward O' Brien, fourth baronet of Dromoland. William's brother was the well-known Sir Lucius O'Brien, Conservative member for Clare. His mother was Charlotte, nee Smith, whose father owned a property called Cahirmoyle in County Limerick. William inherited it and adopted the additional surname of Smith, thereafter he is known as William Smith O'Brien.
He was educated at Harrow and at Cambridge. In the 1820's he took his seat in parliament as the Conservative member for Ennis. In 1835 he became Conservative M.P. for County Limerick. In London he met Mary Ann Wilton and fathered two children born to her. In the Autumn of 1832 he married Lucy Caroline Gabbett of County Limerick. Seven children were born of this union, five boys and two girls.
Originally a Protestant "Country Gentleman" of conservative politics, his views changed with parliamentary experience. He became an ardent supporter of Catholic emancipation. He joined the Repeal Association in 1843. He became a leading member of the Young Irelanders and with Gavan Duffy and others founded the Irish Confederation in 1847. He was active in seeking relief from the hardships of the famine.
1848 was a year of revolution all over Europe. In Ireland, William Smith O' Brien urged the formation of a National Guard, and an armed rising was planned. However, the Famine had left the country spiritless and they had made no real preparations. At the end of July a small group under O' Brien clashed with forty-six policemen at Ballingarry, Co. Tipperary. This skirmish at widow McCormack's cabbage garden brought the rising of 1848 to an inglorious end. William Smith O' Brien was arrested and sent to Clonmel for trial.
The Jury found him guilty of high treason and he was sentenced to be hanged. The capital sentence was commuted to transportation for life. He was imprisoned for about nine months at Spike Island in Cork and on the 29th July 1849, he was sent to Tasmania in company with Meagher, O' Donohue and MacManus, his associates in the Rebellion. After nearly five years in exile an unsolicited pardon was accorded to Smith O' Brien on condition of his not returning to Ireland. In 1854 he came back to Europe, and settled with his family at Brussels. Here he wrote the book "Principles of Government", or Meditations in Exile, which was afterwards published in Dublin. In May, 1856, he was fully pardoned and in July he returned to Ireland. He contributed to the "Nation" newspaper but kept himself apart from politics. After spending a short time at home he departed on a continental tour, visiting North America before his return.
In 1864 he visited England and Wales, with the view of rallying his failing health, but no improvement took place, and he died at Bangor, in Wales on the 16th of June, 1864. He is buried in the family vault in Rathronan, County Limerick
His statue stands in O'Connell Street in Dublin.