At the outbreak of war in 1939, he was called up for military service and in 1940 was taken prisoner by the Germans. He was held at a POW camp in Mainz from 1940 to 1942 before being transferred to a POW camp near Lübeck, where he remained for the rest of the war. While in that camp, Braudel drafted his great work "La Méditerranée et le Monde Méditerranéen à l'époque de Philippe II" ("The Mediterranean and the Mediterranean World in the Age of Philip II"), without access to his books or notes and relying only on his prodigious memory and a local library.