Operation Prejudice

This was the Allied overall designation of naval operations to gain and then retain control of the Sulu Sea and Celebes Sea (1943/44).

Lying between the Philippine islands group and Borneo, the Sulu Sea was vital to the movement of oil products, other raw materials, men, equipment and supplies between the Japanese home islands and the eastern part of the Netherlands East Indies. Lying between the east coast of Borneo, the south coasts of the Philippine islands group and the north coast of Celebes, the Celebes Sea was important to the Japanese for the same reason as the Sulu Sea to its north.