Line infantry
Line infantry was the type of infantry that trained and organized to fight in linear formations, usually arranged two or three ranks deep, to deliver coordinated volleys of musket or rifle fire. This method of warfare began in the late sixteenth and early seventeenth centuries, with its origins commonly attributed to reforms by Maurice of Nassau and the Dutch army. Dutch practices were soon adopted by other European armies and became widespread through military manuals, the movement of officers, and the training of foreign troops by Dutch instructors.
Further development occurred in the eighteenth century under leaders such as Frederick the Great of Prussia, who refined drill, discipline, and the use of concentrated musket fire. His methods made the Prussian infantry a model for other European powers. The tactics and organization of line infantry reached their most widespread application during the Napoleonic Wars, when massed ranks of soldiers firing in volleys formed the core of European armies on large battlefields.
Line infantry continued to play a central role in major conflicts into the nineteenth century. The American Civil War saw some of the last large-scale uses of linear tactics, although changes in weapon technology were already making such formations increasingly risky. The introduction of rifled muskets and then breech-loading rifles, along with advances in artillery, increased the range, accuracy, and lethality of battlefield fire. These changes made dense lines of infantry more vulnerable and reduced the effectiveness of traditional line tactics. By the late nineteenth century, most armies had shifted to looser formations and new approaches to infantry combat, leading to the decline of line infantry as the standard method of organization and fighting.
Development
In the 16th and 17th century most battles where fought in squares or tercios composed of pikemen with smaller squares of musketeers at all four corners. The formation first appeared in Spain in 1534, and was initially composed of 12 companies of 250 men, each company being subdivided into ten squads of 25 men.Advances in weaponry during this period led to major changes in military tactics. Spanish commanders tested various methods to improve the effectiveness of firearms, but Maurice of Nassau introduced the most successful approach in the 1590s. He drew inspiration from Roman military writers and began incorporating exercises such as forming and reforming ranks, drilling, and parading. William Louis of Nassau, Maurice’s cousin, realized after reading Aelian’s Tactics that rotating ranks of musketeers could maintain a steady rate of fire. This system allowed soldiers to fire in groups, then move to the back to reload while another group fired, creating a continuous stream of musket fire and addressing the slow firing rate of muzzle-loading muskets.
This development changed how armies deployed on the battlefield. Forces now spread out more, both to increase the effectiveness of their own gunfire and to lessen their vulnerability to enemy fire. The linear arrangement of troops meant more soldiers could fire at the enemy at once, which increased the lethality of engagements. However, this also meant that more soldiers faced direct combat, requiring greater discipline, skill, and courage from each individual. Success depended on soldiers and entire units executing complex maneuvers quickly and in coordination. To achieve this, the Nassau family reduced the size of military units for better training and control.
Companies became smaller, and large regiments were replaced by more manageable battalions. Count John of Nassau contributed to these reforms by creating drill books and founding a military academy at Siegen in 1616 to educate young officers. The curriculum included practical instruction with weapons, maps, and models, and the academy’s first director published manuals based on Dutch methods. These Dutch training techniques and tactical systems quickly spread throughout Europe, especially in Protestant regions, as many foreigners served in the Dutch army or learned from published treatises. Dutch military instructors also worked abroad. The influence of these reforms reached North America as well. The Virginia Company recruited English veterans of the Dutch army for leadership roles, and many early colonial leaders had Dutch military experience. Officers trained in Dutch methods led militias in Virginia, Massachusetts, and other English colonies, shaping the military practices of settlers in early seventeenth-century English America.
Linear tactics and function
Line infantry mainly used three formations in its battles: the line, the square, and the column.With the universal adoption of small arms in infantry units from the mid-17th century, the battlefield was dominated by linear tactics, according to which the infantry was aligned into long thin lines, shoulder to shoulder, and fired volleys. A line consisted of two, three, or four ranks of soldiers.
The soldiers were expected to fire volleys at the command of officers, but in practice this happened only in the first minutes of the battle. After one or two volleys, each soldier charged his musket and fired at his own discretion, without hearing the commands of the officers. This disrupted the system, while the gunsmoke prevented accurate shooting. Such a shootout in clouds of smoke could occur for an extended period of time and the result was unpredictable. In addition, at the time of the “hot” shootout, the soldiers were so engaged and focused on shooting that they were not watching out for an attack of cavalry from the flank.
For these reasons, experienced officers tried to avoid such uncertain exchanges and restrained their soldiers from premature firing in order to get as close to the enemy’s line as possible so that they could deliver several devastating volleys at a short distance. In some cases, it was possible to defeat the enemy with just one volley at close range.
The line was considered the fundamental battle formation as it allowed for the largest deployment of firepower. Against surrounding enemy cavalry, line infantry could swiftly adopt square formations to provide protection. Such squares were hollow, unlike the pikemen's and old-style musketeers' square.
File:Fontenoy Charles Hay & Enteroches.jpg|thumb|The French Guards Regiment and the British 1st Regiment of Foot Guards invite each other to fire first during the Battle of Fontenoy, 11 May 1745
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 behind if threatened. Movement in line formation was slow, and unless the battalion was superbly trained, a breakdown in cohesion was assured, especially in uneven or wooded terrain. As a result, the line was mostly used as a firing formation, with troops moving in column formations and then deploying to the line at their destination. Usually, columns would be adopted for movement and melee attacks. Line infantry was trained in the manual of arms evolutions, the main objectives of which were fast deployment of a line, rapid shooting, and manoeuvre.
Training and recruitment
Line infantry quickly became the most common type of infantry in European countries. Musketeers and grenadiers, formerly elite troops, gradually became part of the line infantry, switching to linear tactics.Over time the use of line infantry tactics spread outside of Europe, often as a result of European imperialism. In European colonies and settlements with small populations from the home country, line infantry forces were often raised from the local population, with the British East India Company's sepoys perhaps being the most historically significant example.
Line tactics required strict discipline and simple movements practiced to the point where they became second-nature. During training, the drill and corporal punishments were widely used. During 1814, in the War of the Sixth Coalition, the training of regular French line infantry recruits was limited due to the relentless attack of the Coalition Forces. A recruit was trained by firing only two cartridges and four blanks. There was also light training of forming several formations. However, training large quantities of elite line infantry was generally a complicated process.
Arms and equipment
In the middle of the 16th century, the matchlock muskets of some line infantry were equipped with bayonets. Bayonets were attached to the muzzles and were used when line troops entered melee combat. They also helped to defend against cavalry.At the end of the 17th century, a solution was sought to a flaw within the design of matchlock muskets. Since the matchlock musket used a slow burning piece of twine known as a slow match, the twine sometimes would accidentally set fire to the gunpowder reservoir in the musket prematurely setting off the gunpowder, resulting in serious injury or death to the operator. For this reason and others, matchlock muskets began to be replaced by lighter and cheaper infantry fusils with flintlocks, weighing with a caliber of, first in France and then in other countries. In many countries, the new fusils retained the name "musket". Both muskets and fusils were smoothbore, which lessened their accuracy and range, but made for faster loading, lesser amount of bore fouling and more robust, less complicated firearms.
The accuracy of smooth-bore muskets was in the range of against a line of infantry or cavalry. Against a single enemy, however, the effective range was no more than. It should be borne in mind that ordinary linear infantrymen were poorly trained in aimed shooting, due to the expense of gunpowder and lead. Line infantrymen were trained in rapid reloading. The recruit was expected to load 3 rounds a minute, while an experienced soldier could load 4–6 rounds per minute. In battle conditions, this number was reduced and after the first few minutes of combat, no more than 2 rounds per minute could be expected even from well trained troops.
The bulk of the line infantry had no protective equipment, as armor that could provide protection from musket fire were considered too expensive and heavy. Only the former elite troops could keep by tradition some elements of protection, for example, the copper mitre caps of grenadiers.