The Battle of the Philippine Sea was an important naval battle of the Second World War between the navies of the United States and Japan. This battle took place on June 19 and 20, 1944 near the Mariana Islands, and involved two big naval forces and many Japanese aircraft from bases on land. The battle was a great defeat for the Japanese Navy, which lost three aircraft carriers and some 600 aircraft in two days of combat. This happened because the Japanese airplanes were getting old and their pilots had little training, compared to the more modern and better trained American forces. After the battle, the Japanese Navy was almost completely destroyed. This victory for Allied forces opened the door for the invasion of Iwo Jima.