War engines or firearms too large to be managed by a single soldier. Ballistas, onagers, and catapults were early examples of artillery. Their use was largely restricted to siege warfare and it was in such operations that the cannon came to replace them. Modern artillery functions in the same way as all firearms, but fires larger projectiles over longer distances. Muzzle‐loaders, common from the 15th to the 19th century, had their explosive charge and ammunition loaded from the front of the barrel. Breech‐loaders, used in the 15th and 16th centuries and reintroduced on a large scale in the mid‐19th century, have the charge and shot loaded at the rear. Modern categories of artillery fire solid shot, shrapnel, or explosive shells. They include field guns, which fire with a flat trajectory, howitzers and mortars, which have arching trajectories, antitank guns, firing high‐velocity shot, and self‐propelled guns. Since 1918 there has been a decline in the importance of heavy artillery as missiles, bomber aircraft, and armed helicopters have taken over many of their roles, while mortars have taken over many light artillery roles.