1) Japan invaded the Philippines in 1941 as part of its plan to control the region and prevent the islands from being used as an American base of operations. 2) The US and Philippine forces suffered major defeats at the Battles of Bataan and Corregidor, resulting in their surrender in 1942 and the start of three years of harsh Japanese occupation. 3) Philippine resistance continued throughout the occupation in the form of underground groups and guerilla fighters who provided intelligence to the returning US forces under General MacArthur in 1944.