The critical battle during World War II that took place in 1944 in the Pacific theater was the Battle of Leyte Gulf. Fought in October 1944, it was one of the largest naval battles in history and a significant turning point in the war against Japan. The battle involved a massive engagement between American and Japanese forces, with the United States aiming to liberate the Philippines and disrupt Japanese naval power. The defeat of the Japanese navy at Leyte Gulf severely diminished their capability to conduct fleet operations, leading to a shift in momentum towards the Allies and paving the way for future victories in the Pacific.