Rees was born in
Bristol in 1836, the son of James Rees, a surgeon, and Elizabeth Pocock. Rees' father died when he was young, and he was brought up by his mother and uncle. Rees was a member of the famous cricketing
Grace family, with his mother's sister, Martha Pocock, the mother of
WG Grace. He emigrated to
Melbourne, with his mother, in 1851, at the start of the
Victorian gold rush. He married Hannah Elizabeth "Annie" Staite in Melbourne on 8 July 1863, whom he had seven children with, including
Annie Lee "Lily" Rees (1864–1949), a writer, teacher and lawyer;
Elizabeth Lusk (1868–1934), a writer; and
Rosemary Frances Rees (1875–1963), an author, actress, theatre producer and playwright, who founded one of the first theatre companies in New Zealand. ==Cricket career==