The 13th Marine Regiment (13th Marines) was an artillery regiment of the United States Marine Corps. The regiment was activated for service three times during the 20th century when the Marine Corps expanded to meet war time requirements. Originally activated as an infantry regiment during World War I, the unit arrived in France before the war ended but did not participate in combat operations. It was reactivated for service in World War II as the artillery regiment for the 5th Marine Division. The unit saw intense combat during the Battle of Iwo Jima, participated in occupation duty in Japan and was quickly decommissioned shortly after the war. The regiment was last activated during the Vietnam War to again provide fire support for 5th Marine Division regiments supporting operations in Sou