Artillery

Artillery consists of ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons were developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower.

Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannon, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called barrel artillery, cannon artillery or gun artillery) and rocket artillery. In common speech, the word "artillery" is often used to refer to individual devices, along with their accessories and fittings, although these assemblages are more properly called "equipment". However, there is no generally recognized generic term for a gun, howitzer, mortar, and so forth: the United States uses "artillery piece", but most English-speaking armies use "gun" and "mortar". The projectiles fired are typically either "shot" (if solid) or "shell" (if not solid). Historically, variants of solid shot including canister, chain shot and grapeshot were also used. "Shell" is a widely used generic term for a projectile, which is a component of munitions.

By association, artillery may also refer to the arm of service that customarily operates such engines. In some armies, the artillery arm has operated field, coastal, anti-aircraft, and anti-tank artillery; in others these have been separate arms, and with some nations coastal has been a naval or marine responsibility.

In the 20th century, target acquisition devices (such as radar) and techniques (such as sound ranging and flash spotting) emerged, primarily for artillery. These are usually utilized by one or more of the artillery arms. The widespread adoption of indirect fire in the early 20th century introduced the need for specialist data for field artillery, notably survey and meteorological, and in some armies, provision of these are the responsibility of the artillery arm. The majority of combat deaths in the Napoleonic Wars, World War I, and World War II were caused by artillery. In 1944, Joseph Stalin said in a speech that artillery was "the god of war".

Although not called by that name, siege engines performing the role recognizable as artillery have been employed in warfare since antiquity. The first known catapult was developed in Syracuse in 399 BC. Until the introduction of gunpowder into western warfare, artillery was dependent upon mechanical energy, which not only severely limited the kinetic energy of the projectiles, but also required the construction of very large engines to accumulate sufficient energy. A 1st-century BC Roman catapult launching 6.55 kg (14.4 lb) stones achieved a kinetic energy of 16 kilojoules, compared to a mid-19th-century 12-pounder gun, which fired a 4.1 kg (9.0 lb) round, with a kinetic energy of 240 kilojoules, or a 20th-century US battleship that fired a 1,225 kg (2,701 lb) projectile from its main battery with an energy level surpassing 350 megajoules.

From the Middle Ages through most of the modern era, artillery pieces on land were moved by horse-drawn gun carriages. In the contemporary era, artillery pieces and their crew relied on wheeled or tracked vehicles as transportation. These land versions of artillery were dwarfed by railway guns; the largest of these large-calibre guns ever conceived – Project Babylon of the Supergun affair – was theoretically capable of putting a satellite into orbit. Artillery used by naval forces has also changed significantly, with missiles generally replacing guns in surface warfare.

Over the course of military history, projectiles were manufactured from a wide variety of materials, into a wide variety of shapes, using many different methods in which to target structural/defensive works and inflict enemy casualties. The engineering applications for ordnance delivery have likewise changed significantly over time, encompassing some of the most complex and advanced technologies in use today.

In some armies, the weapon of artillery is the projectile, not the equipment that fires it. The process of delivering fire onto the target is called gunnery. The actions involved in operating an artillery piece are collectively called "serving the gun" by the "detachment" or gun crew, constituting either direct or indirect artillery fire. The manner in which gunnery crews (or formations) are employed is called artillery support. At different periods in history, this may refer to weapons designed to be fired from ground-, sea-, and even air-based weapons platforms.