Background
The son of William Duff of Dipple, in 1719 he married Lady Janet Forbes, second daughter of James Ogilvy, Earl of Findlater and widow of Hugh Forbes, Younger of Craigievar.
The son of William Duff of Dipple, in 1719 he married Lady Janet Forbes, second daughter of James Ogilvy, Earl of Findlater and widow of Hugh Forbes, Younger of Craigievar.
He inherited substantial estates from his father on his death in 1722. He commissioned the construction of Duff House in Banff in 1740. He died in 1763, and was buried in the parish church of Grange, before being moved to the mausoleum at Duff House.
The eldest, James, succeeded his father as Earl.
He was Member of Parliament for Banffshire from 1727-1734, and was created Lord Braco of Kilbryde in the Peerage of Ireland on 28 July 1735, and Earl Fife and Viscount Macduff, also in the peerage of Ireland, by letters patent dated 26 April 1759, after proving his descent from the MacDuffs, Earls of Fife. Another son, Arthur, became a member of Parliament.