He was a direct descendant of Augusta FitzClarence, the illegitimate daughter of King William IV, who reigned for seven years until 1837. Second son of Michael Wemyss of that Ilk and chief of Wemyss, and a distant cousin of the 13th Earl of Wemyss (chief of Charteris), Andrew’s maternal grandfather was the 6th Duke of Portland, through his mother, Victoria Cavendish-Bentinck. Victoria, in turn, was the last surviving goddaughter of Queen Victoria, after whom she was named.
At the coronation of King George VI in 1937, Andrew served as a page to his ducal grandfather – whose duties that day centred on carrying the crown of the new queen. Coincidentally, Queen Elizabeth was Andrew’s kinswoman, since her mother was a Cavendish-Bentinck. Further queenly connection occurred through his mother-in-law, Alethea Abel-Smith, also kin.