hamilton became duke of abercorn in the peerage of ireland on the death of his father in june 1979. he was the son of james edward hamilton, 4th duke of abercorn, and lady mary crichton (daughter of lt.-col. henry william crichton, viscount crichton (1872–1914), eldest son of john crichton, 4th earl erne). he is a former politician and lord steward of the household.