18. Treachery Was the Quickest Way to Capture a Medieval Castle
Treachery was the quickest and most efficient way to seize a castle: attackers often induced somebody within the walls to help them sneak in and capture the place. Second quickest way was to storm a castle’s walls with attackers who used ladders and siege towers. However, that was often hazardous, and cost dearly – often prohibitively dearly – in attackers’ lives. One alternative was to try and batter down the walls, either from a distance with catapults and trebuchets, or up close with battering rams. Catapults had been deployed since ancient times against castles and city walls. They used tension or torsion to slowly build up and store energy in a device, before they rapidly released the stored energy via an arm that flung a rock at a targeted wall.
In the later medieval era, catapult technology took a leap forward with the development of trebuchets – the most effective weapon against castle and city walls until the arrival of gunpowder. Traditional catapults relied on torsion or tension to store energy prior to release. By contrast, trebuchets relied on gravity: a heavy weight on one side of a pivot, with a long arm from which a stone was flung on the other side. Trebuchets were faster and easier to construct, and did not use relatively expensive materials like the pricey elastic ropes needed for torsion catapults.