Jisaburō Ozawa
When the Americans landed on Saipan in the Marianas the Japanese viewed holding Saipan as an imperative. Consequently, the Japanese responded with their largest carrier force of the war: the nine-carrier Mobile Fleet under the command of Vice Admiral Jisaburō Ozawa, supplemented by an additional 500 land-based aircraft. Facing them was the US Fifth Fleet under the command of Admiral Raymond A. Spruance, which contained 15 fleet carriers and 956 aircraft. The clash was the largest carrier battle in history. The battle did not turn out as the Japanese had hoped. During the previous month, US destroyers had destroyed 17 out of 25 submarines in Ozawa's screening force and repeated American air raids destroyed the Japanese land-based aircraft.