A brief history of Corregidor taken from corregidorisland.com

Corregidor is a small rocky island in the Philippines about 48 kilometers west of Manila which is stragetically located at the entrance of Manila Bay. This island fortress stands as a memorial for the courage, valor, and heroism of its Filipino and American defenders who bravely held their ground against the overwhelming number of invading Japanese forces during World War II.

Also known as "the Rock," it was a key bastion of the Allies during the war. When the Japanese invaded the Philippines in December 1941, the military force under the command of Gen. Douglas MacArthur carried out a delaying action at Bataan. Corregidor became the headquarters of the Allied forces and also the seat of the Philippine Commonwealth government. It was from Corregidor that Philippine President Manuel Quezon and General MacArthur left for Australia in February 1942, leaving behind Lt. Gen. Jonathan M. Wainwright in command.