Baron Dufferin and Claneboye, of Ballyleidy and Killyleagh in County Down, Northern Ireland, is a title in the Peerage of Ireland. It was created on 30 July 1800 for Dame Dorcas Blackwood, widow of Sir John Blackwood, 2nd Baronet, Member of the Irish Parliament for Killyleagh and Bangor, in return for support for the Union of Ireland and the United Kingdom. History The peerage had been intended for Sir John in return for his support for the Union with the Kingdom of Great Britain. The Blackwood Baronetcy, of Killyleagh in the County of Down, was created in the Baronetage of Ireland in 1763 for Robert Blackwood, the father of Sir John Blackwood. He was the son of John Blackwood and Ursula Hamilton, the daughter and co-heir of Robert Hamilton of Killyleagh, County Down. The Blackwood family, originally of Scottish descent, were prominent landowners in County Down and controlled the borough constituency of Killyleagh in the Irish Parliament. Lady Dufferin and Claneboye was the daughter of James Stevenson, son of Colonel Hans Stevenson and Anne Hamilton, daughter of James Hamilton, son of Archibald Hamilton, of Halcraig, Lanarkshire, brother of James Hamilton, 1st Viscount Claneboye. Her great-grandfather James Hamilton had become the sole heir of Lord Claneboye when the first Viscount's grandson, Henry Hamilton, 2nd Earl of Clanbrassil and 3rd Viscount Claneboye, died in 1675. Lady Dufferin and Claneboye was succeeded by her son, the second Baron, who had already succeeded his father as third Baronet. He represented Killyleagh in the Irish House of Commons and Helston and Aldeburgh in the British House of Commons and was also an Irish Representative Peer from 1820 to 1836. He was childless and was succeeded by his younger brother, the third Baron. The latter's grandson, the fifth Baron, was a prominent Liberal politician, diplomat and colonial administrator, and notably served as Governor General of Canada and Viceroy of India. In 1850, at the age of 23, he was created Baron Clandeboye, of Clandeboye in the County of Down, in the Peerage of the United Kingdom, which gave him a seat in the House of Lords. In 1871 he was created Viscount Clandeboye, of Clandeboye in the County of Down, and Earl of Dufferin, in the County of Down, and in 1888 he was even further honoured when he was made Earl of Ava, in the Province of Burma, and Marquess of Dufferin and Ava, in