# I Marine Expeditionary Force

The I Marine Expeditionary Force ("I" pronounced "One") is a Marine Air Ground Task Force (MAGTF) of the United States Marine Corps primarily composed of the 1st Marine Division, 3rd Marine Aircraft Wing, and 1st Marine Logistics Group. It is based at Marine Corps Base Camp Pendleton.
I Marine Expeditionary Force is the largest of the three MEFs in the Fleet Marine Force and is often referred to as the "Warfighting MEF" for its consistent involvement and contributions in major armed conflicts. It is presently commanded by Lieutenant General Michael Cederholm. The deputy commander is Brigadier General Michael R. Nakonieczny.

## Etymology

Pronunciation of the Roman numeral designator: As a Roman numeral the capital letter "I", representing one, is properly pronounced as "One". However, there are some who erroneously pronounce the number as either "First", or either intentionally, or unknowingly, pronounce it as "Eye", as in the letter "I".
The convention of using Roman numerals to designate a MEF, which is itself the Marine Corps equivalent organization to an Army corps, stems from the U.S. Army practice that began in the American Civil War, and continues today, of numbering corps (two or more divisions with supporting troops, and sometimes including separate brigades, regiments, groups, or battalions, all under a unified corps headquarters, usually commanded by a lieutenant general) with Roman numerals. Corps, themselves being the first-level sub-unit of a "field army", or a numbered, or named, army (e.g., First U.S. Army, or the Army of the Potomac).
During the First World War, the 4th Marine Brigade, as part of the U.S. Army 2nd Infantry Division, came under the U.S. Army I Corps, American Expeditionary Forces. With the expansion of the Marine Corps to six divisions and five air wings during the Second World War, the Marine Corps created two "Amphibious Corps", I Marine Amphibious Corps (later re-designated as III Amphibious Corps) and V Amphibious Corps, continuing the custom begun by the Army. Modern Marine Expeditionary Forces, or MEFs (for a time known as Marine Amphibious [italics added] Forces, or MABs) continue the U.S. Marine Corps legacy as corps-equivalent organizations designated by Roman numerals.

## Mission

When directed, I MEF deploys and is employed as a Marine Air Ground Task Force (MAGTF) in support of Combatant Commander (COCOM) requirements for contingency response or Major Theater War; with appropriate augmentation, serves as the core element of a Joint Task Force (JTF); prepares and deploys combat-ready MAGTF's to support COCOM presence and crisis response; and supports service and COCOM initiatives as required.

## Lineage

NATO Symbol :
* Activated on 8 November 1969 at Okinawa, Japan as the I Marine Expeditionary Force
* Redesignated on 18 August 1970 as the I Marine Amphibious Force (I MAF)
* Relocated in April 1971 to Camp Pendleton, California
* Redesignated on 5 February 1988 as the "I Marine Expeditionary Force"

## Structure
### Units

* Ground combat element: 1st Marine Division
* Aviation combat element: 3rd Marine Air Wing
* Logistics combat element: 1st Marine Logistics Group
* I Marine Expeditionary Force Information Group
** I MEF Support Battalion
** 1st Intelligence Battalion
** 1st Radio Battalion
** 9th Communication Battalion
** 1st Air Naval Gunfire Liaison Company (ANGLICO)
* 11th Marine Expeditionary Unit
* 13th Marine Expeditionary Unit
* 15th Marine Expeditionary Unit

## Recent service

* Operation Desert Shield – Southwest Asia – August 1990 – April 1991
* Operation Desert Storm – Southwest Asia – August 1990 – April 1991
* Operation Restore Hope- December 1992 – May 1993
* Operation Southern Watch – Iraq – January 1998 – February 1998
* Operation Desert Thunder – Iraq – February 1998 – June 1998
* Operation Enduring Freedom – Kuwait, Afghanistan – November 2002
* Operation Iraqi Freedom – Iraq – March 2003 – 2010

## List of commanders

| No. | Commander | Commander | Term | Term | Term | Ref |
| No. | Portrait | Name | Took office | Left office | Term length | Ref |
| - | | Lieutenant General Walter E. Boomer (born 1938) | 15 August 1990 | 6 September 1991 | 1 year, 22 days | - |
| - | | Lieutenant General Robert B. Johnston (born 1937) | 6 September 1991 | July 1993 | ~1 year, 298 days | - |
| - | | Lieutenant General George R. Christmas (born 1940) | July 1993 | July 1994 | ~1 year, 0 days | - |
| - | | Lieutenant General Anthony Zinni (born 1943) | July 1994 | October 1996 | ~2 years, 92 days | - |
| - | | Lieutenant General Carlton W. Fulford Jr. (born 1944) | October 1996 | April 1998 | ~1 year, 182 days | - |
| - | | Lieutenant General Bruce B. Knutson Jr. (born 1946) | April 1998 | 7 July 2000 | ~2 years, 97 days | - |
| - | | Lieutenant General Michael W. Hagee (born 1944) | 7 July 2000 | 18 November 2002 | 2 years, 134 days | |
| - | | Lieutenant General James T. Conway (born 1947) | 18 November 2002 | 12 September 2004 | 1 year, 299 days | - |
| - | | Lieutenant General John F. Sattler (born 1949) | 12 September 2004 | 14 August 2006 | 1 year, 336 days | |
| - | | Lieutenant General James Mattis (born 1950) | 14 August 2006 | 5 November 2007 | 1 year, 83 days | |
| - | | Lieutenant General Samuel T. Helland (born 1947/1948) | 5 November 2007 | 16 October 2009 | 2 years, 348 days | |
| - | | Lieutenant General Joseph Dunford (born 1953) | 16 October 2009 | 19 October 2010 | 1 year, 3 days | |
| - | | Lieutenant General Thomas D. Waldhauser (born 1955) | 19 October 2010 | 12 September 2012 | 1 year, 329 days | |
| - | | Lieutenant General John A. Toolan (born 1954) | 12 September 2012 | 11 July 2014 | 1 year, 302 days | |
| - | | Lieutenant General David H. Berger (born 1959) | 11 July 2014 | 27 July 2016 | 2 years, 16 days | |
| - | | Lieutenant General Lewis A. Craparotta (born 1959) | 27 July 2016 | 30 July 2018 | 2 years, 3 days | |
| - | | Lieutenant General Joseph Osterman (born 1959) | 30 July 2018 | 31 July 2020 | 2 years, 1 day | |
| - | | Lieutenant General Karsten Heckl (born 1964) | 31 July 2020 | 23 September 2021 | 1 year, 54 days | |
| - | | Lieutenant General George W. Smith Jr. | 23 September 2021 | 18 August 2023 | 1 year, 329 days | |
| - | | Major General Bradford J. Gering Acting | 18 August 2023 | 16 February 2024 | 182 days | |
| - | | Lieutenant General Michael S. Cederholm | 16 February 2024 | Incumbent | 1 year, 19 days | |