[3] David completed his national service with the Royal Air Force during the Korean War, initially training as a pilot officer.
[4] In 1956, at the age of 29, he played a prison officer in Joan Littlewood's Theatre Workshop production of Brendan Behan's The Quare Fellow.
One of his first successes in the historical genre was 1972's The Strauss Family followed by many other productions, including The Duchess of Duke Street in 1976–77, 1978's Disraeli, starring Ian McShane and his 1986 Primetime Emmy Award-winning Lord Mountbatten: The Last Viceroy with Nicol Williamson in the title role.
[2] Circumstances also permitted an occasional return to acting, as in his own teleplays of the 1974–78 prison television series Within These Walls, in some episodes of which he played the penal institution chaplain, Rev.
[5] During this time, he was nominated for an Academy Award for his historical screenplay of 1976's Voyage of the Damned, depicting the 1939 attempt by 937 Jews to escape the looming Holocaust via a ship traveling from Hitler's Germany to Havana, but denied permission to disembark in Cuba or in the United States.