Siege engines ranged from the Catapult of the ancient times to the huge Trebuchet of the Middle Ages. Designed to take out fortifications, they consisted of a large mechanical arm that propelled heavy stones and other missiles from a great distance, battering down walls and inflicting damage on buildings and defenders. Though cumbersome and nearly useless on the battlefield, Siege Engines remained the most effective weapon for attacking cities and fortified enemies until the advent of Cannon.