First established on June 14, 1905, the 4th Fleet was created after the Battle of Tsushima in the Russo-Japanese War specifically to support and cover the landings of Japanese forces in Sakhalin.
Afterwards, it was sent to the United States with the Japanese delegation negotiating the Treaty of Portsmouth ending the war, and was disbanded on December 20, 1905.
The Fourth Fleet was temporarily resurrected during a war game exercise executed in 1935, playing the role of the opposition force under the command of Hajime Matsushita.
Nearly all the fleet's destroyers suffered damage to their superstructures, and fifty-four crewmen were lost, swept overboard or killed outright.
A number of new designs that used heavier guns and taller superstructures were found to be top-heavy, and efforts were made to stabilize these ships by reducing weight above the waterline.
However, in November 1943, the Americans attacked the Gilbert Islands and captured the major naval base of Tarawa, which brought the 4th Fleet and its various garrison forces back into the front lines of combat.
The Americans continued to advance through the Marshall Islands in early 1944, neutralizing the Japanese bastion at Truk Atoll in the Carolines, headquarters of the IJN 4th Fleet, by means of powerful naval air strikes in February, and forcing the removal of Japan's major naval units to Palau, which also proved vulnerable to air attack.