He was his father's fourth but first surviving son. In 1708, as Lord Haddo, he was chosen as a Tory M.P. for County Aberdeen but, as he was the eldest son of a Peer, the House of Commons declared him incapable of sitting for any shire or borough in Scotland. Also in 1708 he married Lady Mary Leslie-Melville and they produced one daughter. At the time of their marriage her father was Governor of Edinburgh Castle, while his father was imprisoned there.
His wife died in 1710 and on 25 April 1716 he married Lady Susan Murray, daughter of the 1st Duke of Atholl, and they produced two children. On 1 June 1721 he was elected a Representative Peer and again in 1722. He took a decided part against Ministers and all the Court measures. In 1725 his second wife died in childbirth and, on 9 December 1729, he married Lady Anne Gordon, daughter of the 2nd Duke of Gordon, and they produced five more children.He died on 30 March 1745 at Edinburgh, in his sixty-sixth year, and his widow died there, 26 June 1791, in her seventy-eighth year.

Source: Leo van de Pas