 In 1925, after the death of the 15th Duke of Somerset, St. Maur petitioned the House of Lords Committee for Privileges to safeguard his claim to the Dukedom, in the hope that he might find proof that his parents were married before his birth.On the death of his grandfather the 12th Duke in 1885, St Maur had been presumed to be illegitimate, and the Dukedom eventually passed to a distant branch of the family.He also placed advertisements in newspapers, offering a £50 reward for any witness to his parents' marriage.