World War II

5th Battalion 11th Marines was activated on 1 May 1942 at New River, North Carolina. In June of that year they deployed to Wellington, New Zealand. They were re-designated on 1 January 1943 as the 4th Battalion, 11th Marines. During the war they participated in the following campaigns:

• Battle of Guadalcanal
• Eastern New Guinea
• New Britain
• Battle of Peleliu
• Battle of Okinawa

Following the surrender of Japan, the battalion was deployed to Tientsin, China as part of the occupation of northern China from October 1946 to January 1947. In January they returned to the United States to Marine Corps Base Camp Pendleton, California and were reassigned to the 3rd Marine Brigade. The battalion was deactivated on 17 February 1947. Later that year they were again activated on 16 July only to be deactivated again on 30 September.

Korean War

The battalion was reactivated on 4 August 1950 at MCB Camp Pendleton and were assigned to the 1st Marine Division. In August they deployed to Kobe, Japan and fought in the war until the Korean Armistice Agreement was signed on 27 July 1953. They participated in the following campaigns:

• Inchon/Seoul Campaign
• Battle of Chosin Reservoir
• East/Central Front
• Western Front

Following the war the battalion remained in Korea and participated in the occupation of the Korean Demilitarized Zone from August 1953 until March 1955 when they relocated to MCB Camp Pendleton

Vietnam War

The battalion was relocated to the Marine Corps Air Ground Combat Center Twentynine Palms, California. In February 1966 the battalion deployed to the Republic of Vietnam as part of the 1st Marine Division. They fought in Vietnam Until October 1970 operating from Chu Lai and Danang. They returned to the MCAGCC Twentynine Palms and were deactivated on 15 November 1974.

1980s and 1990s

The 4th Battalion, 11th Marines was reactivated on 15 February 1979 at MCAGCC Twentynine Palms, California from units that had comprised the 1st Field Artillery Group. They were redesignated as 5th Battalion, 11th Marines on 1 October 1984.

The regiment participated in Operation Desert Storm from August 1990 until March 1991. During July and August 1994 the battalion helped fight major forest fires in the western United States.

Iraq

The battalion participated in the 2003 invasion of Iraq and has made subsequent deployments to Iraq as part of Operation Iraqi Freedom (OIF). During the 2003 invasion (OIF I), 5/11 participated on every major battle including the siege of Baghdad, Al Kut and Tikrit (Saddam Hussein's home town). The battalion fired more artillery rounds and drove further in less time than any artillery battalion in history during the invasion, and set the bar as the only artillery unit involved in Task Force Tripoli. In July 2006, Marines from Tango and Siera Batteries were deployed as part of the 15th MEU (Marine Expeditionary Unit, Special Operations Capable) to the Al Anbar province of Iraq. In August 2004, Marines from Romeo Battery participated in the Battle of Najaf.

Afghanistan

In 2010, Battery T, attached to 1st Marine Division's 1st MEF deployed to Camp Leatherneck, Helmand Province, Afghanistan. They returned in early August 2010.^[1] June 2011 – Feb 2012 romeo battery Helmand province. In 2012, Sierra Battery deployed to Now Zad.^[2] In July 2013, Quebec Battery deployed to Camp Leatherneck, Camp Bastion, and Fob Eredvi [Helmand Province] to relieve Sierra Battery. In 2014, Tango battery deployed to Camp Bastion, Helmand Province, Afghanistan.^[3] July 2014 to Nov 2014 Sierra Battery deployed with the mission to provide fire support and assist in the retrograde. Sierra Battery was never relieved and was the last firing battery in the Helmand Province.