The 1st Amphibious Brigade was established on 16 November 1943 under the command of Lieutenant General Yoshimi Nishida out of the Manchukuo-based IJA 3rd Independent Garrison Unit. In mid-December 1943, the brigade embarked and arrived shortly afterwards at Truk, where it was placed under the IJN 4th Fleet. Imperial General Headquarters assigned it to Eniwetok to counter an expected Allied invasion: however, the brigade lost in the sinking of the "Aikoku Maru" at Truck on 17 February 1944 during Operation Hailstone. Another 800 men, including Lieutenant General Nishida were annihilated during the Battle of Eniwetok from 17–23 February 1944 by the United States Marine Corps. The remaining men and transports were sent to Palau and were incorporated into the IJA 53rd Independent Mixed Brigade in May 1944.