Robert George Grosvenor, 5th Duke of Westminster, was born 24 April 1910 in London, Greater London, England, United Kingdom to Hugh William Grosvenor (1884-1914) and Mabel Florence Mary Crichton (1882-1944) and died 19 February 1979 Ely Lodge, Enniskillen, County Fermanagh, Ireland of unspecified causes. He married Viola Maud Lyttelton (1912-1987) 3 December 1946 .
|Offspring of Robert George Grosvenor, 5th Duke of Westminster and Viola Maud Lyttelton (1912-1987)|
|Leonora Mary Grosvenor (1949-)|
|Gerald Cavendish Grosvenor, 6th Duke of Westminster (1951-2016)|
|Jane Meriel Grosvenor (1953-)|