Galley tactics were the dominant form of naval tactics used from antiquity to the late 16th century when sailing ships began to replace oared ships as the principal form of warships. Throughout antiquity and the Middle Ages until the 16th century, the weapons relied on were the ship itself, used as a battering ram or to sink the opponent with naval rams, the mêlée weapons of the crew, missile weapons such as bolts from heavy crossbows fixed on the bulwarks, bows and arrows, weights dropped from a yard or pole rigged out, and the various means of setting an enemy alight. The latter could be done by shooting arrows with burning tow or by Greek fire ejected through specially designed siphons.