david robert somerset, 11th duke of beaufort (23 february 1928 – 16 august 2017), known as mr david somerset until 1984, was a british peer. he served as a member of the house of lords from 5 february 1984 to 11 november 1999. he was president of the british horse society between 1988 and 1990, and was chairman of marlborough fine art.