 The U.S. Navy called it Operation Forager. This mammoth invasion, commonly known as the D-Day of the Pacific, involved 535 ships and 127,571 assault troops. Operation Forager proposed to liberate the Marianas Islands by reclaiming the U.S. territory of Guam and by occupying the nearby islands of Saipan and Tinian. The seizure of these islands formed the lynchpin of Admiral Chester Nimitz's strategy in the Central Pacific. Once taken, these islands could serve as forward bases, giving the United States new options for the next stage of the Pacific War. With the Marianas under their control, U.S. forces could head south and liberate the Philippines, or they could move north through the Bonnens and attack the Japanese home islands. Even more importantly, U.S. Army air forces could establish airfields in the Marianas from which they could launch long-range bombing missions over Japan. A prolonged bombing campaign could, in theory, soften up the home islands for invasion, or perhaps it could even win the war entirely on its own. In any event, the Marianas needed to be taken. Operation Forager was the plan to do it. To carry out this important operation, Admiral Nimitz selected the Navy's fifth fleet under command of Vice Admiral Raymond Spruance. While carrying members of the 27th Infantry Division and the 2nd, 3rd, and 4th Marine Divisions, Spruance's fleet planned to encircle the islands, bombard the landing beaches, and then send in the assault troops. By late April 1944, all the details were set. Vice Admiral Richmond Kelly Turner, the commander of 5th Fleet's amphibious ships, scheduled the first landing on Saipan to take place on June 15th, departing from the Hawaiian islands in early June 1944, 5th Fleet sallied forth, and by the 12th, Spruance's carrier planes began their aerial bombardment of Japanese shore defenses. Turner's amphibious forces landed on schedule, and with that, the two-month battle for the Marianas Islands commenced. As the Marines and Army infantry slogged their way inland, the U.S. Navy now had orders to repel anything the Japanese might do to disrupt the invasion. Unsurprisingly, Japanese naval commanders were eager to strike back. Back in the spring, Fleet Admiral Minichi Koga devised Order 73, also known as Operation Ago, which envisioned a single decisive battle to change the momentum of the Pacific War. Order 73 did not specify a location for this battle, but it supposed that the Imperial Combined Fleet could counterattack in the midst of an American amphibious assault. Unfortunately for Admiral Koga, he never implemented his plan. On March 31st, he was killed when a seaplane in which he was traveling crashed in the middle of a typhoon. As soon as Koga's replacement, Admiral Swaymu Toyoda learned that Americans were coming ashore in the Marianas, he decided to dust off Order 73 and put it into effect. He called upon Vice Admiral Jisaburo Ozawa's mobile force to set sail from Tawi-Tawi and take out Spruance's 5th Fleet. Ozawa assembled a massive fleet of 62 ships and 24 submarines. On June 16th, Ozawa's ships exited through the San Bernardino and Serragao Straits. Several U.S. submarines on patrol detected these convoys and radioed the news of the impending Japanese arrival to Spruance's flagship, USS Indianapolis. Additionally, direction-finding technology at Pearl Harbor pinpointed a possible location for the Japanese Task Force after Ozawa broke radio silence to make contact with his airbases on Guam. Although he possessed accurate sighting reports, Spruance refused to order an immediate counterattack. Even though his carrier Task Force commander, Vice Admiral Mark Mitchell, proposed to sail west and bring the U.S. fleet in range of the Japanese by morning, Spruance denied him. He believed the entirety of the 5th Fleet needed to remain next to Saipan. Spruance later commented, It was of highest importance that our troops and transport forces on and in the vicinity of Saipan be protected, and a circular movement by enemy forces be guarded against. This decision later led to controversy. Mitchell commanded a large and capable force, the Fast Carrier Task Force. When it was attached to 5th Fleet, the Fast Carrier Task Force was called Task Force 58 and it consisted of 112 warships. Mitchell believed his force could be Ozawa's on its own, and when Spruance's orders arrived at Mitchell's flagship, a great many officers assigned to Task Force 58 were beside themselves with anger and accused Spruance of having no guts. Dutifully, Mitchell adhered to his orders. Whether right or wrong, Spruance's decision made it clear that an epic battle would take place in the Philippine Sea and that the Japanese would choose the time of first contact. For two days, June 19th and 20th, 1944, the fate of the Pacific War hung in the balance. In the following videos, you will hear the words of participants from the Battle of the Philippine Sea. Many of the veterans who fought there have since passed on, but before they died, they left behind vivid accounts of their experiences. Voice actors will read aloud their words to bring their recollections back to life. From them, we can learn what it was like to have witnessed one of the biggest naval air battles in world history.