The Battle of Midway was a major naval battle in the Pacific Theater of World War II that took place 4–7 June 1942, six months after the Empire of Japan's attack on Pearl Harbor and one month after the Battle of the Coral Sea. The U.S. Navy under Admirals Chester W. Nimitz, Frank J. Fletcher, and Raymond A. Spruance defeated an attacking fleet of the Imperial Japanese Navy under Admirals Isoroku Yamamoto, Chūichi Nagumo, and Nobutake Kondō north of Midway Atoll, inflicting devastating damage on the Japanese fleet. Military historian John Keegan called it "the most stunning and decisive blow in the history of naval warfare", while naval historian Craig Symonds called it "one of the most consequential naval engagements in world history, ranking alongside Salamis, Trafalgar, and Tsushima Strait, as both tactically decisive and strategically influential."

The Combined Fleet was the main sea-going component of the Imperial Japanese Navy. Until 1933, the Combined Fleet was not a permanent organization, but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime.