Infantry and infant share a root meaning without speech
The word infantry traces back through French and Italian to the Latin infans, meaning speechless or newborn, the same source as infant. In Renaissance Italy and Spain, infanteria meant foot soldiers too green to ride with the cavalry. English picked up infantry in the 1570s, but infantryman arrived only in 1837.
Foot soldiers were the first armies. Early warriors wielded hunting weapons in loose bands, but by the era of the first empires, roughly 2500 to 1500 BC, some troops carried standard equipment and drilled in formations. Such trained regulars were costly, so rulers often padded them with short-term levies of irregulars, a habit that lasted almost into modern times. Until chariots appeared around 2000 BC, every army was purely infantry, and apart from exceptions such as the Mongols, foot soldiers have usually formed the largest part of any force.
After Rome fell, heavy cavalry such as knights dominated Western battlefields, backed by peasant militias. Late in the Middle Ages, skilled light troops such as English longbowmen in the Hundred Years' War showed they could defeat mounted knights. Swiss pikemen and German Landsknechts then revived heavy infantry, using dense walls of pikes to drive off horsemen. Tightly packed ranks were vulnerable to missiles, however, and crossbows, hand cannon and arquebuses let armies field large numbers of shooters without years of archery training. Musketeers carrying bayonets from the mid-17th century gradually replaced the pike.
To maximise firepower, musket-armed troops fought in long lines facing the enemy, which is why they were called line infantry, while light infantry skirmished in looser order with flexible tactics. Unit names often outlived their weapons: grenadiers were once grenade throwers and fusiliers carried the fusil, and regiments such as the Grenadier Guards keep those titles. Dragoons began as infantry who rode to battle and then dismounted. As rifles grew deadlier from the mid-19th century, even regular cavalry spent more time fighting on foot. The British Army numbered its infantry as regiments of Foot from the mid-18th century until 1881.
Today trucks carry motorised infantry to battle, while mechanised infantry ride armoured personnel carriers that can fight themselves, some evolving into infantry fighting vehicles approaching light tanks. Despite tanks and aircraft, infantry remains central to combined operations.
Source: Infantry
