This day in history, February 1, 1943, Japanese forces on Guadalcanal Island, defeated by Marines, started to withdraw after the Japanese emperor finally gave them permission.
On July 6, 1942, the Japanese landed on Guadalcanal Island, part of the Solomon Islands chain, and began constructing an airfield. In response, the U.S. launched Operation Watchtower, in which American troops landed on five islands within the Solomon chain, including Guadalcanal. The landings on Florida, Tulagi, Gavutu, and Tananbogo met with initial opposition from the Japanese defenders, despite the fact that the landings took the Japanese by surprise due to bad weather that had grounded their scouting aircraft.
More than 11,000 Marines landed, but 24 hours passed before the Japanese manning the garrison knew what had happened. The U.S. forces quickly met their main objective of taking the airfield and the outnumbered Japanese troops temporarily retreated. Japanese reinforcements were landed, though, and fierce hand-to-hand jungle fighting ensued. The Americans were at a particular disadvantage because they were assaulted from both sea and air, but when the U.S. Navy supplied reinforcement troops, the Americans gained the advantage.
By February 1943, the Japanese retreated on secret orders of their emperor. The Japanese retreat was so secretive that the Americans did not even know it had taken place until they stumbled upon abandoned positions, empty boats, and discarded supplies.
In total, the Japanese lost more than 25,000 men compared with a loss of 1,600 by the Americans. Both sides lost 24 warships each.