The Martini–Henry is a breech-loading single-shot lever-actuated rifle that was used by the British Army. It first entered service in 1871, eventually replacing the Snider–Enfield, a muzzle-loader converted to the cartridge system. Martini–Henry variants were used throughout the British Empire for 30 years. It combined the dropping-block action first developed by Henry O. Peabody (in his Peabody rifle) and improved by the Swiss designer Friedrich von Martini, combined with the polygonal barrel rifling designed by Scotsman Alexander Henry.
Though the Snider was the first breechloader firing a metallic cartridge in regular British service, the Martini was designed from the outset as a breechloader and was both faster firing and had a longer range.
There were four main marks of the Martini–Henry rifle produced: Mark I (released in June 1871), Mark II, Mark III, and Mark IV. There was also an 1877 carbine version with variations that included a Garrison Artillery Carbine, an Artillery Carbine (Mark I, Mark II, and Mark III), and smaller versions designed as training rifles for military cadets. The Mark IV Martini–Henry rifle ended production in 1889, but remained in service throughout the British Empire until the end of the First World War. It was seen in use by some Afghan tribesmen as late as the Soviet invasion. Early in 2010 and 2011, United States Marines recovered at least three from various Taliban weapons caches in Marjah, and another was found near Orgun in Paktika Province by United States Army's 101st Airborne Division (Air Assault).
The Martini–Henry was copied on a large scale by North-West Frontier Province gunsmiths. Their weapons were of a poorer quality than those made by Royal Small Arms Factory, Enfield, but accurately copied down to the proof markings. The chief manufacturers were the Adam Khel Afridi, who lived around the Khyber Pass. The British called such weapons "Pass-made rifles".