Light infantry

Light infantry (or skirmishers) are soldiers whose job was to provide a skirmishing screen ahead of the main body of infantry, harassing and delaying the enemy advance. Light infantry was distinct from medium, heavy or line infantry. Heavy infantry were dedicated primarily to fighting in tight formations that were the core of large battles. Light infantry fought in open-order, often in close co-ordination with heavy infantry, where they could screen the heavy infantry from harassing fire, and the heavy infantry could intervene to protect the light infantry from attacks of enemy heavy infantry or cavalry. Heavy infantry originally had heavier arms and more armour than light infantry, but this distinction was lost as the use of armour declined and gunpowder weapons became standardized.

The concept of a skirmishing screen is a very old one and was already well-established in Ancient Greece and Roman times in the form, for example, of the Greek peltast and psiloi, and the Roman velites. As with so called "light infantry" of later periods, the term more adequately describes the role of such infantry rather than the actual weight of their equipment. Peltast equipment, for example, grew steadily heavier at the same time as hoplite equipment grew lighter. It was the fact that peltasts fought in open order as skirmishers that made them light infantry and that hoplites fought in the battle line in a phalanx formation that made them heavy infantry.

Early regular armies of the modern era frequently relied on irregulars to perform the duties of light infantry skirmishers. In the 17th century, dragoons were the light infantry skirmishers of their day – lightly armed mounted infantrymen who rode into battle but dismounted to fight, giving them a mobility lacking to regular foot soldiers.

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