Sir Richard Attenborough (General Charles Whiteley) and Gerald Sim (Dr. Griffiths) were brothers-in-law in real-life. Attenborough was married to Sim's elder sister Sheila Sim from 1945 until his death in 2014.
Richard Attenborough had spent over a year working on his directorial debut, "Oh, What A Lovely War!" without any payment whatever and thereafter threw himself into a great deal of acting work to make some money. This was one of several films he made in 1969-70, more for the lavish salary than any belief that a good film would eventuate.
Sir Richard Attenborough (General Charles Whiteley) directed John Thaw (Terry Mitchell) in Cry Freedom - Le cri de la liberté (1987) and Chaplin (1992).
The working title was "Grigsby". It was changed only a short time before its opening.