artillery, originally meant any large weaponry (including such ancient engines of war as catapults and battering rams) or war material, but later applied only to heavy firearms as opposed to small arms. Types of artillery include antiaircraft and antitank guns (which fire at high muzzle velocity through long barrels at flat trajectories) and howitzers (with shorter barrels, lower velocities, and parabolic trajectories). The term cannon can apply to almost all heavy artillery, especially howitzers, and even to automatic guns on aircraft. Mortars and batteries of small tactical rockets are usually used as artillery. Modern artillery came into use in the mid-14th cent. with the introduction of gunpowder in the West. At first, the new cannon were used mainly against fortifications. Its impact was demonstrated by the Ottoman Turks, who used giant guns cast on the battlefield to breach the walls of Constantinople and capture it in 1453. Cannon also revolutionized war at sea (see navy). Artillery was first extensively employed in the field during the Thirty Years War (1618-48); thereafter it played an increasingly important role until the advent of aircraft. Now that few pieces of fixed artillery (e.g., coastal defense guns) still survive, artillery is generally classified as either towed or self-propelled. Artillery was characteristically smoothbore and muzzle-loaded, firing solid, round shot, until the latter part of the 19th cent., when breech-loaded, rifled, and shell-firing artillery became standard.