Line infantry is a type of infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

 which composed the basis of European land armies from the middle of the 17th century to the middle of the 19th century.

Line infantry appeared in the 17th century. At the beginning of 17th century the Swedish king Gustavus Adolphus decided to equip his army with firearms with wheellock

Wheellock

A wheellock, wheel-lock or wheel lock, is a friction-wheel mechanism to cause a spark for firing a firearm. It was the next major development in firearms technology after the matchlock and the first self-igniting firearm. The mechanism is so-called because it uses a rotating steel wheel to provide...

s, but only his cavalry received them in his lifetime. Shortly after his death, the Swedish infantry was equipped with new musket

Musket

A musket is a muzzle-loaded, smooth bore long gun, fired from the shoulder. Muskets were designed for use by infantry. A soldier armed with a musket had the designation musketman or musketeer....

s with wheellocks which were comparatively light when compared to older muskets, making it easier to fire the weapon without the aid of a support. Moreover, the new musket required less iron and it turned out to be cheaper to mass produce. This firearm made it possible to create line infantry.

Linear Tactics and Function

Line infantry used mostly three types of 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 handgun

Handgun

A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns ....

s) in the infantry units from the middle of 17th century the battlefield was dominated by linear tactics

Line (formation)

The line formation is a standard tactical formation which has been used in Early modern warfare.It continues the phalanx formation or shield wall of infantry armed with polearms in use during antiquity and the Middle Ages....

, 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 maximising enemy casualties. 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 formation

Infantry square

An infantry square is a combat formation an infantry unit forms in close order when threatened with cavalry attack.-Very early history:The formation was described by Plutarch and used by the Romans, and was developed from an earlier circular formation...

s to provide protection. Such squares were hollow (consisting of four lines), unlike the pikiners' and old-style musketeers' square.

Movement in line formation

Line (formation)

The line formation is a standard tactical formation which has been used in Early modern warfare.It continues the phalanx formation or shield wall of infantry armed with polearms in use during antiquity and the Middle Ages....

 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 formation

Column (formation)

A military column is a formation of soldiers marching together in one or more files in which the file is significantly longer than the width of ranks in the formation...

s and then deploying to line at their destination. Usually for movement and melee attacks columns would be adopted.

Line infantry was trained in the manual of arms

Manual of arms

A manual of arms was an instruction book for handling and using weapons in formation, whether in the field or on parade. Such manuals were especially important in the matchlock and flintlock eras, when loading and firing was a complex and lengthy process typically carried out in close order...

 evolutions, the main objectives of which were fast deployment of a line, rapid shooting and manoeuvre.

Training and recruitment

Line tactics required a strict discipline and simple movements, practised to the point where they became second-nature. During training, the drill and corporal punishments were widely used.

Line infantry quickly became the most common type of infantry in European countries. Musketeer

Musketeer

A musketeer was an early modern type of infantry soldier equipped with a musket. Musketeers were an important part of early modern armies, particularly in Europe. They sometimes could fight on horseback, like a dragoon or a cavalryman...

s and grenadiers, formerly elite troops, gradually became part of the line infantry, switching to linear tactics.

Arms and equipment

In the middle of the 17th centure the muskets of line infantry had bayonets added. Bayonet

Bayonet

A bayonet is a knife, dagger, sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, effectively turning the gun into a spear...

s were attached to the muzzle of muskets and were used when line troops entered melee

Mêlée

Melee , generally refers to disorganized close combat involving a group of fighters. A melee ensues when groups become locked together in combat with no regard to group tactics or fighting as an organized unit; each participant fights as an individual....

 combat. They also helped to defend against cavalry.

At the end of the 17th century muskets were replaced by lighter and cheaper infantry fusils

Fusilier

Fusilier was originally the name of a soldier armed with a light flintlock musket called the fusil. The word was first used around 1680, and has later developed into a regimental designation.-History:...

 with flintlock

Flintlock

Flintlock is the general term for any firearm based on the flintlock mechanism. The term may also apply to the mechanism itself. Introduced at the beginning of the 17th century, the flintlock rapidly replaced earlier firearm-ignition technologies, such as the doglock, matchlock and wheellock...

s, weighing 5 kg with a caliber of 17.5 mm, first in France and then in other states. In many countries the new fusils retained the name "musket". Both muskets and fusils were smoothbore

Smoothbore

A smoothbore weapon is one which has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars.-History of firearms and rifling:...

 which lessened their accuracy and range.

The bulk of the line infantry had no protective equipment. Only the former elite troops could keep by tradition some elements of protection, for example, the copper mitre caps of grenadiers.

Line infantry and other contemporary types of infantry

Initially line infantry was only a small part of infantry, because it was originally vulnerable to hostile cavalry. Pikiner

Pikiner

Pikiners were European warriors of the 16th and 17th centuries armed with a pike....

s were the majority of infantry and were known as heavy infantry. A significant part of infantry consisted of old-style musketeers, who did not use the linear tactics. However by the middle of the 17th century line infantry already provided about half of the infantry in most Western European armies. After the invention of the bayonet, line infantry could defend itself from the enemy's horsemen. The percentage of pikiners fell gradually. In 1689 the Austrian army got rid of pikiners. In 1703 the French army did the same. In 1699-1721 Peter I

Peter I

Peter I may refer to:Religious hierarchs:*Pope Peter, papal name sometimes referring to the Apostle Peter *Patriarch Peter I of Alexandria Rulers:*Tsar Peter I of Bulgaria...

 converted almost all Russian infantry to line infantry. Line infantry now comprised the bulk of the infantry of European armies.

Besides line infantry, there were elite troops (royal guards and other designated elite regiments) and the light infantry. Light infantry operated in extended order (also known as skirmish formation) as opposed to the close orders (tight formations) used by line infantry. Since the late 18th century light infantry in most European countries mostly consisted of riflemen

Rifleman

Although ultimately originating with the 16th century handgunners and the 17th century musketeers and streltsy, the term rifleman originated from the 18th century. It would later become the term for the archetypal common soldier.-History:...

 (such as the German Jäger

Jäger (military)

Jäger is a term that was adopted in the Enlightenment era in German-speaking states and others influenced by German military practice to describe a kind of light infantry, and it has continued in that use since then....

), armed with expensive rifled carbines and trained in aimed shooting and use of defilade

Enfilade and defilade

Enfilade and defilade are concepts in military tactics used to describe a military formation's exposure to enemy fire. A formation or position is "in enfilade" if weapons fire can be directed along its longest axis. A unit or position is "in defilade" if it uses natural or artificial obstacles to...

s. Line infantry, whose muskets with bayonets were heavier than carbines, became known as heavy infantry and were used as the main deciding force.

In France during the Revolutionary

French Revolutionary Wars

The French Revolutionary Wars were a series of major conflicts, from 1792 until 1802, fought between the French Revolutionary government and several European states...

 and Napoleonic Wars

Napoleonic Wars

The Napoleonic Wars were a series of wars declared against Napoleon's French Empire by opposing coalitions that ran from 1803 to 1815. As a continuation of the wars sparked by the French Revolution of 1789, they revolutionised European armies and played out on an unprecedented scale, mainly due to...

 the division into the Guard, line infantry and light infantry formally continued to exist, but line regiment

Regiment

A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...

s and "light" regiments had identical weaponry (smooth-bore fusils) and tactics. Napoleon distrusted rifled firearms. However, both line and "light" regiments each included a battalion of tirailleurs or voltigeurs

Voltigeurs

The Voltigeurs were French military skirmish units created in 1804 by Emperor Napoleon I.-Etymology:Voltigeurs hold their name from their originally conceived role of cavalry-transported skirmishers: the voltigeurs were intended to jump onto the croup of cavalry horses in order to advance more...

 expected to act as skirmishers as well being able to deploy into line.

The Russian infantry of 1853 comprised 110 regiments. 52 of which were line infantry, 10 regiments were Guard, and 46 regiments were light infantry (42 Jäger regiments and 4 infantry carabinier

Carabinier

A Carabinier was originally a cavalry soldier armed with a carbine...

 regiments). However, only a part of the Russian light infantry were equipped with rifles.

In the 19th century the percentage of riflemen in European armies increased, and the percentage of line infantry equipped with muskets fell. In the American Civil War both Northern and Confederate armies had only a few line regiments. However, France, due to Napoleon III, who admired Napoleon I, had 300 line battalions (comprising an overwhelming majority) even in 1870. Although the French line infantry received Chassepot rifles in 1866, it still was being trained in the use of closed formations: line, column and square, which was changed only after the dethronement of Napoleon III.

Battlefield Obsolescence

In the years after the Napoleonic Wars, line infantry continued to be deployed as the main battle force while light infantry provided fire support and covered the movement of units. In Russia, Great Britain, France and some other states, linear tactics and formation discipline were maintained into the late 19th century (examples: Crimean War

Crimean War

The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...

, Franco-Prussian War

Franco-Prussian War

The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...

).

With the invention of new weaponry, the concept of line infantry began to wane. The Minié ball

Minié ball

The Minié ball is a type of muzzle-loading spin-stabilising rifle bullet named after its co-developer, Claude-Étienne Minié, inventor of the Minié rifle...

 (an improved rifle ammunition), allowed individual infantrymen to shoot more accurately and over greatly increased range. Men walking in formation line-abreast became far too easy a target, as evidenced in the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

. By the end of this conflict breech-loading rifles

Breech-loading weapon

A breech-loading weapon is a firearm in which the cartridge or shell is inserted or loaded into a chamber integral to the rear portion of a barrel....

 were adopted, which gave the individual shooter even greater increased rate of fire as well. In the 1860s most German states and Russia converted their line infantry and riflemen into the united infantry, which used rifles and skirmish tactics. After the Franco-Prussian War both German Empire and France did the same. However, Great Britain retained the name "line infantry", although it used rifled muskets from 1853, breech loading rifles from 1867, and switched from closed lines to extended order during Boer wars.

The growing accuracy and rate of fire of rifles and the invention in 1883 of the Maxim gun

Maxim gun

The Maxim gun was the first self-powered machine gun, invented by the American-born British inventor Sir Hiram Maxim in 1884. It has been called "the weapon most associated with [British] imperial conquest".-Functionality:...

 machine gun meant that close orders of line infantry would suffer huge losses before being able to close with their foe, while the defensive advantages given to line infantry against cavalry became irrelevant with the effective removal of offensive cavalry

Cavalry

Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...

 from the battlefield in the face of the improved weaponry. With the turn of the 20th Century this slowly led to infantry increasingly adopting skirmish style light infantry

Light infantry

Traditionally light infantry were 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...

 tactics in battle, while retaining line infantry drill for training.

Retention of "line infantry" title

While, as detailed above, linear battle tatics had become obsolete by the second half of the nineteenth century, regiments in a number of European armies continued to be classified as "line infantry" (or cavalry). This designation had come to mean the regular or numbered regiments of an army, as opposed to specialist or elite formations. Accordingly the distinction had become one of traditional title or classification without significance in respect of armament or tactics. As an example the Belgian Army of 1914 comprised 14 regiments of Infanterie de Ligne (line infantry), three of Chasseurs a pied (light infantry), one of Grenadiers and one of Carabiniers. Similar differentiations were made in the majority of European armies of the period. The modern UK army retains the traditional distinction between "line infantry" and "the Rifles", although all are armed with rifles and none use linear tactics. Equally, infantry of most 21st century armies are still trained in formation manoeuvre and drill, as a way of instilling discipline

Discipline

In its original sense, discipline is referred to systematic instruction given to disciples to train them as students in a craft or trade, or to follow a particular code of conduct or "order". Often, the phrase "to discipline" carries a negative connotation. This is because enforcement of order –...

 and unit cohesion

Unit cohesion

Unit cohesion is a military concept, defined by one former United States Chief of staff in the early 1980s as "the bonding together of soldiers in such a way as to sustain their will and commitment to each other, the unit, and mission accomplishment, despite combat or mission stress"...

.