Educated for a military career in the British Army, Major Hargreaves served in France, Gallipoli, and again in France during World War I. Severely wounded in May, 1917, while serving as a Divisional Staff Officer, he was retired after the war and has devoted himself to the serious study of history, interrupted by a return to uniform in 1939-45. He has written many articles and a number of books, of which the latest, The Enemy At The Gate, is a study of twelve famous sieges.