He achieved popularity in the mid 1950s after making 38 appearances on the television series The Adventures of Robin Hood. He appeared as 'Pete' in Harold Pinter's The Birthday Party on its very first run in 1958, this being just one of countless stage performances he made. Though over-shadowed by his stage career, Gray made a handful of incredibly popular films, notably The Mummy (1959), as a priest in Laurence Olivier's film Richard III, the James Bond film A View to a Kill (1985) as an insane former Nazi professor, and as the elderly and kind king in The Princess Bride (1987). In Sergei Bondarchuk's film Waterloo (1970), he is credited as both an actor (playing Captain Ramsey) and a military consultant. In the late 1980s, he appeared in the BBC drama Howards' Way as banker Sir John Stevens. Gray died at the age of 76 in 1993. His wife, Felicity Gray, was a choreographer and speaker on ballet, who notably taught Gene Tierney for her role in Never Let Me Go.