Infantry

The infantry is the branch of a military force that fights on foot. As the troops who are intended to engage, fight, and defeat the enemy in face-to-face combat, they bear the brunt of warfare and typically suffer the greatest number of casualties. Historically, as the oldest branch of the combat arms, the infantry are the tip of the spear of a modern army, and continually undergo training that is more physically stressful and psychologically demanding than that of any other branch of the combat arms.

Infantry can enter and maneuver in terrain that is inaccessible to military vehicles and employ crew-served infantry weapons that provide greater and more sustained firepower. The transport and delivery techniques of modern infantrymen to engage in battle include marching, mechanised transport, airborne by parachute or by air assault from helicopter and amphibious landing from the sea.

History and etymology

In English, the 16th-century term Infantry (ca. 1570s) describes soldiers who walk to the battlefield, and there engage, fight, and defeat the enemy in direct combat, usually to take and occupy the terrain. As describing the branch of the combat arms, the term Infantry derives from the French Infanterie, which, in turn, is derived from the Italian Fanteria and ultimately from the Latin Infantera; the individual-soldier term Infantryman (1837) was not coined until the 19th century. Historically, before the invention and the introduction of firearms to warfare, the foot soldiers of previous eras—armed with blunt and edged weapons, and a shield—also are considered and identified as infantrymen.

Regiment

A regiment is a military unit. Their role and size varies markedly, depending on the country and the arm of service.

In Medieval Europe, the term "regiment" denoted any large body of front-line soldiers, recruited or conscripted in one geographical area, by a leader who was often also the feudal lord of the soldiers.

By the 17th Century, a full-strength regiment was usually about a thousand personnel, and was usually commanded by a colonel.

Definitions

During the modern era, the word "regiment" – much like "corps" – may have two somewhat divergent meanings, which refer to two distinct roles:

In many armies, the first role, of front-line unit, has been assumed by independent battalions, battlegroups, task forces, brigades and/or other, similarly-sized operational units. However, these non-regimental units tend to be short-lived, and regiments, have tended to retain their traditional responsibilities for: ceremonial duties, the recruitment of volunteers, induction of new recruits, morale/esprit de corps and administrative roles (such as pay).

509th Infantry Regiment (United States)

The 509th Infantry Regiment is an airborne infantry regiment of the United States Army. Previously titled the 509th Parachute Infantry Regiment (509th PIR) was the first parachute infantry unit of the U.S. Army to make a combat jump during World War II. Currently its 1st and 3rd battalions are active. The 1st Battalion serves as the Opposing Force (OPFOR) at the Army's Joint Readiness Training Center at Fort Polk, Louisiana. The 3rd Battalion is assigned to the 4th Brigade Combat Team (Airborne), 25th Infantry Division, at Fort Richardson, Alaska.

Creation

With the advent of World War II, the United States Armed Forces foresaw a need for highly mobile units that the Allies could quickly insert into the theater of battle. The 509th PIR was originally constituted on 14 March 1941 as the 504th Parachute Battalion and activated on 5 October 1941 at Fort Benning, Georgia. The 503rd and 504th Parachute Infantry Battalions were joined together to form the 503rd Parachute Infantry Regiment on 24 February 1942 at Fort Bragg, NC. The 504th PIB was reorganized and redesignated as the 2nd Battalion, 503rd Parachute Infantry Regiment, and its Companies A, B, and C were redesignated as Companies D, E, and F, respectively, of the 503rd PIR.