In early September 1942 Japanese marines attacked a strategic Royal Australian Air Force base at Milne Bay, near the eastern tip of Papua. They were beaten back by the Australian Army, and the Battle of Milne Bay was the first outright defeat of Japanese land forces during World War II. The offensives in Papua and New Guinea of 1943–44 were the single largest series of connected operations ever mounted by the Australian armed forces. The Supreme Commander of operations was the United States General Douglas Macarthur, with Australian General Thomas Blamey taking a direct role in planning, and operations being essentially directed by staff at New Guinea Force headquarters in Port Moresby. Bitter fighting continued in New Guinea between the largely Australian force and the Japanese 18th Army based in New Guinea until the Japanese surrender in 1945.