Combined Fleet The was the main ocean - going component of the Imperial Japanese Navy . Until 1933 , the Combined Fleet was not a standing force , but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime . History . Sino - Japanese War ( 1894 – 95 ) . The Combined Fleet was formally created on 18 July 1894 by the merger of the " Standing Fleet " and the " Western Fleet " . " The Standing Fleet " ( also known as the Readiness Fleet ) contained the navy ' s most modern and combat - capable warships . The " Western Fleet " was a reserve force consisting primarily of obsolete ships deemed unsuitable for front - line combat operations , but still suitable for commerce protection and coastal defense . Vice - admiral Itoh Sukeyuki was appointed the first Commander - in - Chief of the Combined Fleet . for the duration of the first Sino - Japanese war against China . Russo - Japanese War ( 1904 – 05 ) . The Combined Fleet was re - formed during the Russo - Japanese War of 1904 – 05 to provide a unified overall command for the three separate fleets in the Imperial Japanese Navy . The IJN 1st Fleet was the main battleship force , which formed the backbone of the navy and was intended to be used in a traditional line - of - battle showdown with an equivalent enemy battleship fleet ( " kantai kessen " ) . The IJN 2nd Fleet was a fast , mobile strike force with armored cruiser s and protected cruiser s . The IJN 3rd Fleet was primarily a reserve fleet of obsolete vessels considered too weak for front - line combat service , but which could still be used in the operation to blockade Port Arthur . Admiral Togo Heihachiro was commander - in - chief of the Combined Fleet during the Russo - Japanese War . Interwar years . The Combined Fleet was not a permanent organization , but was temporarily created when necessary — either during wartime or during fleet maneuvers . Thus , during the period from 1905 – 1924 , the Combined Fleet was created only sporadically as the occasion or circumstances dictated , and disbanded immediately afterwards . In 1924 , the Imperial Japanese Navy declared in an edict on fleet organization that " for the time being " the Combined Fleet would be a standing organization consisting of the IJN 1st Fleet and IJN 2nd Fleet . As the commander of IJN 1st Fleet concurrently directed the Combined Fleet , the Combined Fleet did not have a Headquarters staff of its own . From 1933 , with the Manchurian Incident and the increasing tension with China , a permanent HQ staff for the Combined Fleet was established . By the late 1930s , it included most of Japan ' s warships — only the base units , the Special Naval Landing Forces , and the China Area Fleet lay outside the Combined Fleet . World War II . The Combined Fleet came under command of the Imperial General Headquarters in 1937 . With the start of the Pacific War with the attack on Pearl Harbor carried out by the Combined Fleet ' s Kido Butai , the Combined Fleet became almost synonymous with the Imperial Japanese Navy . It comprised the battleships , aircraft carrier s , aircraft , and the components that made up the main fighting strength of the IJN . It was first mobilized on the whole for the Battle of Midway . After the devastating carrier losses at Midway and in the Solomon Islands campaign , the Navy re - organized into a number of " Area Fleets " for local operational control of various geographic zones . The Combined Fleet then evolved into more of an administrative organization . As the war situation deteriorated for the Japanese and the territories controlled by the " Area Fleets " fell one after another to the United States Navy , the Imperial General Headquarters and the Imperial Japanese Navy General Staff acted to force the American fleet into a " decisive battle " in the Philippines per the " kantai kessen " philosophy . In the resultant Battle of the Philippine Sea and the Battle of Leyte Gulf the Japanese fleet was decimated . The remnants of the Combined Fleet fled to Okinawa , but further operations were hindered by lack of fuel and air cover . By the time of the final suicide mission of the battleship " Yamato " in Operation Ten - Go , the Combined Fleet had ceased to exist as an effective combat force . The Combined Fleet was formally dissolved on 10 October 1945 . Commanders of the IJN Combined Fleet . Commander in chief Chief of staff