Founded in 1941, with individual units dating back before then, it is the oldest and largest
active duty division in the United States Marine Corps, representing a combat-ready force of more than 19,000 men and women. It is one of three active duty divisions in the Marine Corps today and is a multi-role, expeditionary ground combat force. It is nicknamed "The Old Breed". The 1st Division saw combat service during almost all major conflicts during the 20th century. It participated in
World War I (only
5th and
11th Marine Regiments of the future Division served in
France),
World War II,
Korean War,
Vietnam War,
Gulf War,
Somali Civil War,
Iraq War and
War in Afghanistan. ==Commanding generals==