Activated 25 August 1943 at Camp Pendleton, California, as Headquarters Company, 1st Battalion, 20th Marines, 4th Marine Division, Fleet Marine Force. Deployed during February 1944 to the Pacific Theater. Redesignated 31 August, as Headquarters and Service Company, 4th Engineer Battalion, 4th Marine Division. Participated in the Battle of Kwajalein, Battle of Saipan, Battle of Tinian and the Battle of Iwo Jima. Redeployed during October 1945 to Maui, Hawaii. Relocated during November 1945 to Camp Pendleton, California, where it was deactivated on 15 November 1945.