Corregidor (kərĕˈgĭdôrˌ) [key], historic fortified island (c.2 sq mi/5 sq km), at the entrance to Manila Bay, just off Bataan peninsula of Luzon island, the Philippines. From the days of the Spanish, Corregidor and its tiny neighboring islets—El Fraile, Caballo, and Carabao—guarded the entrance to Manila Bay, serving as an outpost for the defense of Manila. The Spanish also maintained a penal colony on Corregidor. When the Americans acquired the Philippine Islands after the Spanish-American War (1898), they elaborately strengthened those defenses. Corregidor was honeycombed with tunnels to serve as ammunition depots, and Fort Mills and Kindley Field were established. Fort Drum was built on El Fraile, Fort Hughes on Caballo, and Fort Frank on Carabao. The new fortifications were deemed so formidable that Corregidor became known as the Gibraltar of the East, or "the Rock." In the early phase of World War II, Corregidor's batteries guarded the entrance to Manila Bay—denying that splendid harbor to the Japanese for five months—and protected the flank of the large U.S.-Filipino army concentrated on Bataan peninsula. During those months Corregidor was subjected to one of the most intense continuous bombardments of the entire war. Its surface was churned to rubble, and the garrison was forced into the caves and tunnels. After the fall of Bataan, about 10,000 U.S. and Filipino troops under Lt. Gen. Jonathan M. Wainwright fought gallantly on for a month. They were hopelessly cut off from all supplies and aid. Corregidor was finally invaded early in May, 1942, and the garrison was forced to surrender. The island was recaptured in Mar., 1945, by U.S. paratroopers and shore landing parties. It is now a national shrine.
See J. and W. Belote, Corregidor: The Saga of a Fortress (1967).