Brian Charles Sweeny, who has died aged 81, was a son of the socialite Margaret, Duchess of Argyll.
He was born at the Dorchester Hotel, 5 April, 1940, son of the American businessman Charles Francis Sweeny [1909-93], and his wife the former [Ethel] Margaret Whigham [1912-93], daughter of George Hay Whigham [1878-1960], of Upper Grosvenor St, W1, and his wife the former Helen Marion Mann Hannay [who died 1954].
A sister, Frances Helen Sweeny [born 1937], married 15 May, 1958, as his second wife, the 10th Duke of Rutland, CBE [1919-99], of Belvoir Castle.
Brian Sweeny's parents divorced in 1947, and his mother married 2ndly, 22 March, 1951 [divorced 1963], as his third wife, the 11th Duke of Argyll [1903-1973].
He married in 1978, Judith M. Dubelaar, by whom he had issue, a son Charles Cornelius [born 1981], and a daughter, Stephanie Frances [born 11 Nov, 1983].
The funeral services will be held at the Farm Street Church in Mayfair, 9 November, 2021.