Corps (kɔər; plural corps kɔərz; from French corps, from the Latin corpus "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was first named as such in 1805. The size of a corps varies greatly, but two to five divisions and anywhere from 40,000 to 80,000 are the numbers stated by the US Department of Defense.
Within military terminology a corps may be:
an operational formation, sometimes known as a field corps, which consists of two or more divisions, such as the Corps d'armée, later known as I Corps ("First Corps") of Napoleon I's Grande Armée);
an administrative corps (or mustering) – that is a specialized branch of a military service (such as an artillery corps, a armoured corps, a signal corps, a medical corps, a marine corps, or a corps of military police) or;
in some cases, a distinct service within a national military (such as the United States Marine Corps).
These usages often overlap.
Corps may also be a generic term for a non-military organization, such as the US Peace Corps and European Solidarity Corps.
In many armies, a corps is a battlefield formation composed of two or more divisions, and typically commanded by a lieutenant general. During World War I and World War II, due to the large scale of combat, multiple corps were combined into armies which then formed into army groups. In Western armies with numbered corps, the number is often indicated in Roman numerals (e.g., VII Corps).
The Australian and New Zealand Army Corps was raised in 1914, consisting of Australian and New Zealand troops, who went on to fight at Gallipoli in 1915. In early 1916, the original corps was reorganized and two corps were raised: I ANZAC Corps and II ANZAC Corps. In the later stages of World War I, the five infantry divisions of the First Australian Imperial Force (AIF)—consisting entirely of personnel who had volunteered for service overseas—were united as the Australian Corps, on the Western Front, under Lieutenant General Sir John Monash.