The special value of the firelock in armies of the 17th century lay in the fact that the artillery of the time used open powder barrels for the service of the guns, making it unsafe to allow lighted matches in the muskets of the escort. Further, a military escort was required, not only for the protection, but also for the surveillance of the artillerymen of those days. Companies of firelocks were therefore organized for these duties, and out of these companies grew the fusiliers who were employed in the same way in the wars of Louis XIV. In the latter part of the Thirty Years' War (1643) fusiliers were simply mounted troops armed with the fusil, as carabiniers were with the carbine. But the escort companies of artillery came to be known by the name shortly afterwards, and the regiment of French Royal Fusiliers, organized in 1671 by Vauban, was considered the model for Europe.
The general adoption of the flintlock musket and the suppression of the pike in the armies of Europe put an end to the original special duties of fusiliers, and they were subsequently employed to a large extent in light infantry work, perhaps on account of the greater individual aptitude for detached duties naturally shown by soldiers who had never been restricted to a fixed and unchangeable place in the line of battle.
Today, however, such regiments are simply known as "infantry", although most modern French army regiments descend from fusilier regiments.
Only the French Navy and French Air Force use the title fusilier today. The navy's marines are known as sea fusiliers (Fusiliers Marins) and the Air Force's ground infantry are known as Air Fusiliers.
The eight regiments of fusiliers that existed in 1914 have been reduced by a series of disbandments and mergers to:
Prior to March 2006, a further two regiments of fusiliers existed in the British Army:
These two regiments were then amalgamated into larger regiments. The names exist within battalions of these new regiments:
In the Prussian Army of 1870, Infantry Regiments 33 to 40 plus Regiments 73 (Hanover), 80 (Hesse-Kassel or Hesse-Cassel) and 86 (Schleswig-Holstein) were all designated as fusiliers, as was the Guard Fusilier Regiment. In addition the third battalions of all Guard, Grenadier and Line infantry regiments retained the designation 'Fusilier Battalion'. They were armed with a slightly shorter version of the Dreyse Rifle (Füsiliergewehr), that took a sword bayonet (Füsilier-Seitengewehr) rather than the standard socket bayonet. Although still theoretically skirmishers, in practice they differed little from their companions, as all Prussian infantry fought in a style that formed a dense 'firing' or 'skirmish' line.
By the 1880s the title was honorific and, while implying 'specialist' or 'elite', did not have any tactical significance. In a sense all infantry were becoming fusiliers, as weapons, tactics and equipment took on the fusilier characteristics - that is: skirmish line, shorter rifles, sword bayonets and black leather equipment. Nonetheless these titular units remained in existence until the end of the German Imperial Army in 1918, as follows:
In addition, there was the following regiment:
This was a special case, as it was also classed as 'Schützen' (Sharpshooter): this designation originally signified a type of 'Jäger' (Rifleman), and thus the regiment wore the Jäger-style dark green uniform.
The various Fusilier regiments and battalions in the German Imperial Army of 1914 did not have any single distinctions of dress or equipment to distinguish them as fusiliers. Individual regiments did however have special features worn with the dark blue full dress. Some of these features were maintained on the field grey dress of the trenches right up to 1918. As examples in full dress, the Guard Fusiliers had nickel buttons, yellow shoulder straps and black plumes and the 80th Fusiliers special braiding on collars and cuffs deriving from their origin as the Elector of Hesse's Guards.
In World War II the elite German Division Großdeutschland contained a regiment titled Panzerfuesiliere ('Panzer Fusiliers'), to maintain the old German traditions. The modern German Army has no fusiliers.
The Belgian Navy used to have a regiment of marine infantry composed of marine fusiliers in charge of the protection of the naval bases. This unit has now been disbanded in the 1990s reforms however.