A large group of soldiers that forms the main body of an army. The infantry first truly came about with the miltary development of the Phalanx in Ancient Greece; This was a large, tight square-like formation of Greek soldiers carrying shields and very long lances that marched towards the enemy. These formations would continue for over two millienia, where soldiers would be organized in closely-formed lines (rows) and columns, and these which would gradually grow away from the thick, square-like formations into longer and thinner lines and taller, narrow columns. This move away from block-type formations allowed the infantry to have more movement and flexibility.
Infantry tactics and weaponry would continue to develop through the many centuries. The greatest era of the infantry was during the more-than-a-century long period from the French and Indian War (Mid-1750s to 1763) all the way to the Franco-Prussian War (1870). During this time, warfare saw the move from musketeers to riflemen, and also regular cannons to rifled artillery, as the process of "rifling" not only applied to battle rifle
s, but to artillery guns as well. During the greater part of the 19th Century, infantry tactics became known as "Napoleonic Tactics", named after the great Corsican general who catapulted all the way to Emperor of France
, and eventually the temporary ruler of most of Europe. However, with the introduction of more-lethal rifled and repeating weapons by the time of the American Civil War
, the tactics involving long, 2-3 rank battle lines of soldiers and tightly-packed formations in rows and columns marching in unison would have to change.
By the time of the Spanish-American War, tactics would change, as platoons, regiments, and battalions would find newer and less-dangerous methods of approaching and defending against the enemy. Today, infantry is truly different in the means of its tactics, weaponry, and the fact that they use vehicles, too. The infantrymen on military jeeps and trucks are known as "mechanized infantry". The infantry still makes up the major part of armies, and are included in both the Marines and the Army.
Infantry has always been the most important element of every single army.