セイロン沖海戦
Following the Japanese conquest of Southeast Asia east of Burma by the end of February 1942, submarines of the Imperial Japanese Navy were moving freely throughout the north and eastern expanses of the Indian Ocean. In March, Japanese aircraft carriers conducted the Indian Ocean raid upon shipping in the Bay of Bengal and bases in Colombo and Trincomalee in Ceylon (now Sri Lanka). This raid drove the British Eastern Fleet out of the area and they were forced to relocate to a new base at Kilindini Harbour, Mombasa, Kenya.