educated at st edward's school, oxford, and the royal military academy sandhurst, thorne was commissioned into the royal norfolk regiment in 1952. he was a keen cricketer and played two first-class matches for the combined services cricket team in 1964. he also played minor counties matches for norfolk from 1954 to 1962, as did his twin brother, michael (1955–1958), and uncle, gordon thorne (1914–1925).