Ian Sumner is a prolific writer and researcher who specializes in local and military history. He has made a particular study of the French army during the First World War, his many books on the subject including French Army 1914-18, French Poilu 1914-18 and First Battle of the Marne 1914. He is the author, with François Vauvillier, of French Army 1939-45, and has also published books on the Royal Navy, the British army, the Indian Army, the Anzacs, the German air force and the history of Yorkshire.