The matchlock was the first mechanism invented to facilitate the firing of a hand-held firearm. Before this, firearms (like the hand cannon) had to be fired by applying a lit match (or equivalent) to the priming powder in the flash pan by hand; this had to be done carefully, taking most of the soldier's concentration at the moment of firing, or in some cases required a second soldier to fire the weapon while the first held the weapon steady. Adding a matchlock made the firing action simple and reliable by a single soldier, allowing him to keep both hands steadying the gun and eyes on the target while firing.
The classic European matchlock gun held a burning slow match in a clamp at the end of a small curved lever known as the serpentine. Upon the pull of a lever (or in later models a trigger) protruding from the bottom of the gun and connected to the serpentine, the clamp dropped down, lowering the smoldering match into the flash pan and igniting the priming powder. The flash from the primer travelled through the touch hole igniting the main charge of propellant in the gun barrel. On release of the lever or trigger, the spring-loaded serpentine would move in reverse to clear the pan. For obvious safety reasons, the match would be removed before reloading of the gun. Both ends of the match were usually kept alight in case one end should be accidentally extinguished.
Earlier types had only an "S"-shaped serpentine pinned to the stock either behind or in front of the flash pan (the so-called "serpentine lock"), one end of which was manipulated to bring the match into the pan.
Most matchlock mechanisms mounted the serpentine forward of the flash pan. The serpentine dipped backward, toward the firer, to ignite the priming. This is the reverse of the familiar forward-dipping hammer of the flintlock and later firearms.
A later addition to the gun was the rifled barrel. This made the gun much more accurate at longer distances but did have drawbacks, the main one being that it took much longer to reload because the bullet had to be pounded down into the barrel.
A type of matchlock was developed called the snap matchlock, in which the serpentine was held in firing position by a weak spring, and released by pressing a button, pulling a trigger, or even pulling a short string passing into the mechanism. As the match was often extinguished after its relatively violent collision with the flash pan, this type fell out of favour with soldiers, but was often used in fine target weapons.
An inherent weakness of the matchlock was the necessity of keeping the match constantly lit. The match was steeped in potassium nitrate to keep the match lit for extended periods of time. Being the sole source of ignition for the powder, if the match was not lit when the gun needed to be fired, the mechanism was useless, and the weapon became little more than an expensive club. This was chiefly a problem in wet weather, when damp match cord was difficult to light and to keep burning. Another drawback was the burning match itself. At night, the match would glow in the darkness, possibly revealing the carrier's position. The distinctive smell of burning match-cord was also a giveaway of a musketeer's position (this was used as a plot device by Akira Kurosawa in his movie Seven Samurai). It was also quite dangerous when soldiers were carelessly handling large quantities of gunpowder (for example, while refilling their powder horns) with lit matches present. This was one reason why soldiers in charge of transporting and guarding ammunition were amongst the first to be issued self-igniting guns like the wheellock and snaphance.
The matchlock was also uneconomical to keep ready for long periods of time. To maintain a single sentry on night guard duty with a matchlock, keeping both ends of his match lit, required a mile of match per year.
The matchlock appeared in Europe in the mid-15th century, with the idea of a serpentine appearing in an Austrian manuscript. The first dated illustration of a matchlock mechanism dates to 1475 (making it the first firearm with a trigger) and by the 16th century they were universally used. During this time the latest tactic in using the matchlock was to line up and send off a volley of musket balls at the enemy. This volley would be much more effective than single soldiers trying to hit individual targets.
David Nicolle theorizes that the Janissary corps of the Ottoman army were using matchlock arms from the 1440s onwards, but this theory has no evidence. Robert Elgood theorizes Ottoman and Italian army used the arquebus in 15th century, but this may be a type of hand cannon, not matchlocks with trigger mechanism. He agreed that the matchlock first appeared 1470s in Germany.
China is credited with inventing both gunpowder and firearms but the matchlock was claimed to have been introduced to China by the Portuguese. Europeans refined the hand cannons that had arrived in Europe in the early 15th century and added the matchlock mechanism. The Chinese obtained the matchlock arquebus technology from the Portuguese in the 16th century and matchlock firearms were used by the Chinese into the 19th century. The Chinese used the term "bird-gun" to refer to muskets and Turkish muskets may have reached China before Portuguese ones.
In Japan, the first documented introduction of the matchlock, which became known as the tanegashima, was through the Portuguese in 1543. The tanegashima seems to have been based on snap matchlocks that were produced in the armory of Goa in Portuguese India, which was captured by the Portuguese in 1510. While the Japanese were technically able to produce tempered steel (e.g. sword blades), they preferred to use work-hardened brass springs in their matchlocks. The name tanegashima came from the island where a Chinese junk with Portuguese adventurers on board was driven to anchor by a storm. The lord of the Japanese island Tanegashima Tokitaka (1528–1579) purchased two matchlock rifles from the Portuguese and put a sword smith to work copying the matchlock barrel and firing mechanism. Within a few years, the use of the tanegashima in battle forever changed the way war was fought in Japan.
Despite the appearance of more advanced ignition systems, such as that of the wheellock and the snaphance, the low cost of production, simplicity, and high availability of the matchlock kept it in use in European armies until about 1720. It was eventually completely replaced by the flintlock as the foot soldier's main armament.
In Japan, matchlocks continued to see military use up to the mid-19th century. In China, matchlock guns were still being used by imperial army soldiers in the middle decades of the 19th century.
There is evidence that matchlock rifles may have been in use among some peoples in Christian Abyssinia in the late Middle Ages. Although modern rifles were imported into Ethiopia during the 19th century, contemporary British historians noted that, along with slingshots, matchlock rifle weapons were used by the elderly for self-defense and by the militaries of the Ras.
Under Qing rule, the Hakka on Taiwan owned matchlock muskets. Han people traded and sold matchlock muskets to the Taiwanese aborigines. During the Sino-French War, the Hakka and Aboriginals used their matchlock muskets against the French in the Keelung Campaign and Battle of Tamsui. The Hakka used their matchlock muskets to resist the Japanese invasion of Taiwan (1895) and Han Taiwanese and Aboriginals conducted an insurgency against Japanese rule.
Tibetans have used matchlocks from as early as the sixteenth century until very recently. Tibetan nomad fighters used arquebuses for warfare during the Chinese invasion of Tibet as late as the second half of the 20th century. Tibetan nomads still use matchlock rifles to hunt wolves and other predatory animals. These matchlock arquebuses typically feature a long, sharpened retractable forked stand and are part of Tibetan traditional Nomad regalia. Some of these arquebuses are engraved with silver and gold inlays and/or have damascened barrels. The early 20th century explorer Sven Hedin also encountered Tibetan tribesmen on horseback armed with matchlock rifles along the Tibetan border with Xinjiang.