 In 1935 he was accepted into the Royal Military College, Sandhurst.Digby graduated from Sandhurst as an officer with the rank of second lieutenant on 21 January 1937 and was commissioned into the Unattached List for the Indian Army with a view to joining the Indian Army due to his family connections.He was attached to the 2nd Battalion, Oxfordshire and Buckinghamshire Light Infantry in India from 13 March 1937, and subsequently transferred to that regiment 27 April 1938 (never joining the Indian Army) so that he would be able to continue his hobbies of tiger hunting and pig sticking.