Object Title

Siege Engines

Siege engines were the heavy weaponry of the Middle Ages. These large wooden devices, which included catapults and trebuchets, were used to attack everything from small earthwork fortifications to vast walled cities.


Sieges were a significant part of the Hundred Years' War. The English king Henry V successfully besieged the French port of Harfleur in 1415, on his way to Agincourt, and an inspirational young Joan of Arc fought back the English at the Siege of Orléans (1428–29).

Siege engines used simple mechanical energy to fling large projectiles to batter down stone walls or cause destruction within the walls.

There were many different types of siege engines. Some particularly well-known types were catapults, trebuchets, battering rams, and siege towers.

The battering ram was a heavy beam that would be swung or rammed against a door. Most catapults were powered by torsion. A twisted string or rope was held taut and when released it flung the projectile through the air.

The trebuchet was the most common siege engine used during the Hundred Years' War. It was powered by gravity rather than torsion. It worked in a see-saw motion, with a sling and projectile at one end and a counterweight at the other. This mechanism generated more force and threw the object further with more accuracy. It could also throw bigger boulders and therefore cause greater damage. Edward I probably used such an engine against Stirling Castle in 1304. It was given the name 'War Wolf'.

Siege towers were also used at the time of the Hundred Years' War. Siege towers were multi-storey wooden towers containing soldiers, which were wheeled up the walls so that soldiers could climb over the walls and enter the castle. Some could be of great height, such as one used at Lisbon in 1147 which was said to be 29 metres (95 feet) high.

The use of wooden siege engines was gradually superseded by artillery pieces, such as bombards.

Use and effect

Different siege engines could hurl rocks, burning barrels, stone balls, or shot bolts and other projectiles.

Siege engines were just one of the ways to besiege a site. If they could not break down the walls with their siege engines, then a besieging army might attempt to mine the walls and make them collapse, or starve the inhabitants out over a long period of time.

Advances in siege engines encouraged the development of better defences. As the Hundred Years' War progressed, and siege warfare became so strategically important, the French towns became increasingly well-fortified. As well as sheltering behind stronger walls, defenders could also loose arrows down upon the attackers through arrow loops in the walls and from the parapet of the wall. Crossbows were often part of the defensive arsenal of a castle.



Bob Woosnam-Savage