Line infantry

Line infantry is the type of infantry that composed the basis of European land armies from the middle of the 17th century to the middle of the 19th century. For both battle and parade drill it consisted of 2 to 4 ranks of foot soldiers drawn up side by side in rigid alignment, and thereby maximizing the effect of their firepower. By extension, the term came to be applied to the regular regiments "of the line" as opposed to skirmishers, foot guards, militia and other special categories of infantry.

Line infantry mainly used three formations in its battles: the line, the square and the column.

With the massive proliferation of hand guns (firearms that could be carried by hand, as opposed to cannon; not to be confused with handguns) in the infantry units from the middle of 17th century, the battlefield was dominated by linear tactics, according to which the infantry was aligned into long thin lines and fired volleys. A line consisted of 2, 3 or 4 ranks of soldiers.

The relatively short range at which smooth bore muskets could accurately hit a target, added to the slow reload (2 to 3 rounds per minute), meant that massed formation firing was essential for maximizing shock by means of firing at the center of the opposing line. During the time period that line infantry were prevalent, the object was to cause the enemy formation to rout, which was done by breaking it, and thus plunging it into disarray. This is why they fired all at once, on command, rather then at will, even though it was less effective in causing actual casualties, as firing was done only as fast as the slowest man could reload his weapon. The line was considered as the fundamental battle formation as it allowed for the largest deployment of firepower. Troops in skirmish formation, though able to take cover and use initiative, were highly vulnerable to cavalry and could not hold ground against advancing infantry columns. Line infantry provided an 'anchor' for skirmishers and cavalry to retreat to if threatened.

Against surrounding enemy cavalry, line infantry could swiftly adopt square formations to provide protection. Such squares were hollow (consisting of four lines), unlike the pikemen' and old-style musketeers' square.

Movement in line formation was very slow, and unless the battalion was superbly trained, a breakdown in cohesion was virtually assured, especially in any kind of uneven or wooded terrain. As a result, line was mostly used as a stationary formation, with troops moving in column formations and then deploying to line at their destination. Usually, columns would be adopted for movement and melee attacks.

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