His eldest son and heir apparent Archibald Hamilton-Temple-Blackwood, Earl of Ava, was killed at the Siege of Ladysmith during the Second Boer War while serving as a war correspondent. He was unmarried and the Marquess was therefore succeeded by the second son, the second Marquess. On his death the titles passed to another brother, the third Marquess. He was a soldier and also served as Speaker of the Senate of Northern Ireland. Lord Dufferin and Ava died in an air crash and was succeeded by his son, the fourth Marquess. He notably held office as Under-Secretary of State for the Colonies in the government of Neville Chamberlain.