1st Battalion 5th Marines 1st Battalion , 5th Marines ( 1 / 5 ) is an infantry battalion in the United States Marine Corps based out of Marine Corps Base Camp Pendleton , California consisting of approximately 800 Marines and sailors . Nicknamed " Geronimo " , it falls under the command of the 5th Marine Regiment and the 1st Marine Division . The battalion was formed in Mexico in 1914 and has served in every major conflict that the United States has been involved in since then . History . On 13 July 1914 , the battalion was formed at Vera Cruz , Mexico , and sailed for Guantanamo Bay , Cuba for service in the Caribbean theatre . The battalion was disbanded upon their return to Norfolk , Virginia , on 24 December 1914 . World War I . On 25 May 1917 , the battalion was activated and deployed to France on 1 June 1917 . 1 / 5 participated in the following World War I campaigns : Aisne , Aisen - Marne , St . Mihiel , Meuse - Argonne , Toulon - Troyon , Chateau - Thierry , Marabache , and Limey . From December 1918 to July 1919 , the battalion participated in the occupation of the German Rhineland . It then re - deployed to Marine Corps Base Quantico , Virginia and de - activated in August 1919 . In July 1920 the battalion re - activated to provide security for the U . S . Mail . In March 1927 , the Battalion deployed to help stabilize the government against overthrow attempts by rebel forces . For the next six years , they aided the Nicaraguan government until peace was finally restored . 1 / 5 was deactivated in January 1933 . Shortly thereafter the battalion was re - activated in September 1934 in Quantico , Virginia and served in the Caribbean theatre until the outbreak of World War II . World War II . In November 1934 , the 1st Battalion was reactivated for the fourth time , only to be deactivated in March 1935 . Shortly before World War II in April 1940 , 1st Battalion was again reactivated . The fighting in World War II found the Marines of 1st Battalion at Guadalcanal , New Guinea , Peleliu , and Okinawa . In April 1946 , their mission accomplished , 1st Battalion was disbanded and most of the Pacific veterans returned to civilian life . Korean War . During October 1949 , 1st Battalion , 5th Marines was reactivated in Camp Pendleton , California . During August 1950 , the Battalion deployed to fight the Communist force invading the Republic of Korea . Names such as the Pusan Perimeter , Inchon , Seoul and Chosin Reservoir were added to the Battalion ' s battle vocabulary . At the close of hostilities , the 1st Battalion returned to the United States , settling at Camp Pendleton . Vietnam War . From June 1966 to March 1971 , 1 / 5 was deployed to Vietnam . The battalion participated in action around Chu Lai , Danang , Quang Nam , Que Son Valley , Hoi An , Phu Loc , and An Hoa . The unit was deactivated in June 1974 but once again was quickly reactivated in March 1975 . The battalion played a major role in the Battle of Hue City during February 1968 . Engaging the enemy in the famous Citadel on the north side of the Perfume River , the battalion became known as the " Citadel Battalion " . Gulf War and the 1990s . From 1987 - 89 , The battalion supported Operation Prime Chance in the Persian Gulf . In August , 1990 , the battalion returned to the Southwest Asia in support of Operation Desert Shield , and subsequently took part in combat operations in Kuwait during Operation Desert Storm . The battalion formed the left half of the mechanized Task Force Ripper , along with 1st Battalion 7th Marines , Alpha Company 1st Tank Battalion , Alpha Company 3rd Tank Battalion , HQ 7th Marines and Delta Company , 3rd Light Armored Infantry Battalion . They were supported by Alpha and Delta Companies of the 3rd Assault Amphibian Battalion , 1st Combat Engineer Battalion and a platoon from Charlie Company , 1st Reconnaissance Battalion . The task force was commanded by Colonel Carlton W . Fulford , Jr . and saw considerable combat as it pushed into Kuwait , seized Al Jaber Airfield and consolidated with other Marine forces at Kuwait International Airport of 27 February 1991 . Following the cease fire , the task force backloaded to Manifeh Bay and departed Saudi Arabia on 8 March . The battalion returned to Camp Pendleton the following day . Global War on Terror . The battalion deployed to Kuwait in 2003 to become part of the invasion force that ousted Saddam Hussein . The Marines of 1 / 5 were the first to enter the country beginning combat operations the day prior to the war beginning . The battalion continued north in the coming weeks before ultimately participating in the battle for Baghdad . They returned again to Iraq as part of Operation Iraqi Freedom in early 2004 for security and stabilization operations in Al Anbar Province . In March 2004 , the battalion , this time attached to the 1st Marine Regiment along with several other units , participated in Operation Vigilant Resolve in the restive city of Fallujah . They were deployed a third time in support of Operation Iraqi Freedom , one of only two Marine Corps infantry battalions to do so at the time , in the city of Ar Ramadi , capital of Al Anbar Province between March and October 2005 . 1 / 5 deployed to Afghanistan from May to December 2009 as part of Task Force Leatherneck and conducted combat operations in the Nawa - I - Barakzayi District of Helmand province . 1 / 5 was once more deployed to Afghanistan from March to October 2011 in support of Operation Enduring Freedom and ISAF to the Sangin District of Helmand Province . During this time they took part in two separate combat operations . Upon completing this rotation they were awarded with the Navy Meritorious Unit Citation award . In September 2012 , 1 / 5 deployed as a Battalion Landing Team ( BLT ) as part of the 31st Marine Expeditionary Unit . 1 / 5 completed a six - month rotation including a deployment to the Kingdom of Thailand in support of exercise Cobra Gold 2013 . The Battalion was relieved by fellow 5th Marines Battalion 2 / 4 and returned to Camp Pendleton in late May 2013 .