In 1885, Queen Victoria created for Alexander Duff the title Earl of Fife in the Peerage of the United Kingdom.

[3] Queen Victoria's Letters Patent of 29 June 1889 creating these titles contained the standard remainder to "heirs male of his body".

On 24 April 1900, Queen Victoria issued another letters patent by which she created for the 1st Duke of Fife the further dignities of Duke of Fife and Earl of Macduff, both in the Peerage of the United Kingdom, and both with a special remainder that allowed these titles to pass to his daughters by Princess Louise, in default of a son, and then to the male heirs of those daughters.

Thirty-three years later, in 1992, The 3rd Duke of Fife also succeeded his father as 12th Earl of Southesk and chief of the Clan Carnegie.

The 4th Duke of Fife's heir apparent is his son Charles Duff Carnegie (born 1989), who uses the courtesy title Earl of Southesk.