William O'Brien
William O'Brien (2 October 1852 – 25 February 1928) was an Irish nationalist, journalist, agrarian agitator, social revolutionary, politician, party leader, newspaper publisher, author and Member of Parliament (MP) in the House of Commons of the United Kingdom of Great Britain and Ireland. He was particularly associated with the campaigns for land reform in Ireland during the late 19th and early 20th centuries as well as his conciliatory approach to attaining Irish Home Rule.
Peter O'Brien, 1st Baron O'Brien
Lord O'Brien married Annie Clarke, daughter of Robert Hare Clarke of Bansha Castle, County Tipperary and his second wife Anne Butler in 1867 and had three children: James, who died young, Ellen (who died in 1930) and Anne Georgina. His only son having predeceased him, he died without male heirs at Airfield, Stillorgan, County Dublin on 7 September 1914, his barony and baronetcy thus becoming extinct.