While operating under Spruance's command as the Fifth Fleet, the fleet took part in the Mariana Islands campaign of June–August 1944, the Iwo Jima campaign of February–March 1945, and the Okinawa campaign of April–June 1945. During the course of these operations, it conducted Operation Hailstone (a major raid against the Japanese naval base at Truk) in February 1944, defeated the Imperial Japanese Navy in the Battle of the Philippine Sea in June 1944, and blunted the Japanese Operation Ten-Go – sinking the Japanese battleship "Yamato" in the process – in April 1945.