Sandys, born on 24 January 1908 at the Manor House, Sandford Orcas, Dorset, was the son of George John Sandys, a Conservative Member of Parliament (1910–1918) and Mildred Helen Cameron.[1] Sandys' parents divorced in January 1921 when he was 12 years old.[2][3] His mother married Frederick Hamilton Lister in October that year, becoming Mildred Helen Lister.[4][5] He was educated at Eton College and Magdalen College, Oxford.