Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The IJN 5th Fleet was a fleet of the Imperial Japanese Navy, active during the early portions of the Second Sino-Japanese War, and again in World War II, primarily in the Battle of the Aleutian Islands. The IJN 5th Fleet was initially formed on 1 February 1938 as part of the Japanese military emergency expansion program in the aftermath of the North China Incident of 1937. The initial plan was to construct 3rd, 4th and 5th China Area Fleets to cover the invasions of Japanese troops into the Chinese mainland, and to interdict and control commerce on the coasts. The IJN 4th and IJN 5th Fleets came under the operational control of the 2nd China Expeditionary Fleet. It participated in the Hainan Island Operation and other maritime interdiction operations off the Chinese coast. The fleet was disbanded on 15 November 1939 when its operations were merged into the China Area Fleet.