If forced to assault a castle, there were many options available to the attackers. For wooden structures, such as early motte-and-baileys, fire was a real threat and attempts would be made to set them alight as can be seen in the Bayeux Tapestry. Projectile weapons had been used since antiquity and the mangonel and petraria – from Eastern and Roman origins respectively – were the main two that were used into the Middle Ages. The trebuchet, which probably evolved from the petraria in the 13th century, was the most effective siege weapon before the development of cannons. These weapons were vulnerable to fire from the castle as they had a short range and were large machines. Conversely, weapons such as trebuchets could be fired from within the castle due to the high trajectory of its projectile, and would be protected from direct fire by the curtain walls.