Born on 30 September 1904, Forbes was baptized on 6 November[1] and his birth was legally registered with the authorities during the last quarter of 1904.

[2] Forbes met with an accident while playing football at Denstone College in Staffordshire which resulted in a scar on his cheek.

[3] He came to the United States as a member of a British troupe that performed Havoc, a war play.

In the United States he appeared onstage opposite actress Ruth Chatterton, whom he wed on 20 December 1924 in New York City.

He married actress Heather Angel in Yuma, Arizona,[6] on 29 August 1934; that marriage ended in divorce on 18 July 1941.