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The Trebuchet, one of the deadliest military machines of its time, is a type of siege engine developed to attack and destroy the solid stone walls of castles.

Using a sophisticated counter balance system, large rocks weighing in excess of 150 kilograms were placed in the catapult sling and hurled with such a force that they could breach the strongest of fortifications.


Located in a key position on outer green, the Trebuchet at Cardiff Castle is an historically accurate replica of a 13th Century siege engine standing at 10 metres (approx. 35 ft high) tall and weighing almost 6 tons.

It was originally built by locally based professional set makers and carpenters to feature in the Hollywood movie, Ironclad (Runnymeade Productions), starring Paul Giamatti, James Purefoy, Brian Cox, Mackenzie Crook, James Flemyng, Derek Jacobi and Kate Mara.

The film chronicles the great siege of Rochester Castle in 1215, when a group of rebel Barons defended one of the most important strategic forts in Britain against the ruthless King John who was hell bent on reclaiming his power following the signing of the Magna Carta.


After its installation, the optimal range and velocity for firing the Trebuchet was calculated with the help of ‘A’ level Maths and Physics students from Cardiff High School. A team of 8 members of the Cardiff Castle staff, ‘The Trebuchet Team’, were also trained to load and fire this frightening piece of medieval technology.

Unfortunately, a defect has since been detected in one of the Trebuchet’s timbers so we are sadly no longer able to operate it due to health and safety concerns.



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