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The longest siege in medieval English history

Published: 16 June 2016
Posted by: English Heritage
Category: History In-depth

In the summer of 1266, noble rebels gathered inside Kenilworth Castle in Warwickshire with supplies and arms, preparing for a siege. England was divided by civil war as King Henry III, who had been on the throne for 50 years, fought against some leading nobles, who wanted to curb his power.

Henry’s assault on the castle began on 25 June 1266, and turned into the longest siege in medieval English history.

Header Image: Stone balls being hurled at a castle by a siege engine similar to the trebuchets used at Kenilworth in 1266. From a French manuscript circa 1340.

Kenilworth Castle: a royal fortress turned rebel stronghold

The rebels’ key asset was Kenilworth Castle. One of the largest fortresses in England, Henry’s father had spent vast sums strengthening its defences. However, Henry III then gave it to Simon de Montfort, his brother-in-law and a leading rebel, probably in an attempt to secure his loyalty.

By giving away one of his most heavily fortified castles, Henry took a huge risk. Although Montfort’s son promised to give Kenilworth back to the king, his father’s supporters inside the castle had other ideas.

The siege started with a messenger’s severed hand

By the time a royal army assembled at Kenilworth Castle in April 1266, a garrison of about 1,200 people including wives, children and servants were ready to defend Kenilworth. They had built up stocks of enough food to hold out for months, and had managed to obtain siege engines.

Henry attempted to persuade the garrison to surrender, but they refused. His patience finally snapped when his messenger returned from the castle with a hand cut off.


A reconstruction drawing of a siege engine similar to those used at the siege of Kenilworth.
© Historic England Photo Library.

An arsenal of siege weapons were employed

On 25 June 1266 a full siege began. The king’s stone-throwing machines bombarded the castle with a stream of missiles. However, the superior range of the weaponry inside meant the king had to send to London for larger machines.

The king was determined to retake the castle and amassed a vast arsenal of weaponry – including 60,000 crossbow bolts and nine siege engines.

Disease and starvation for the defenders

The siege wore on for 6 months, with the rebels refusing to accept Henry’s terms of surrender. Disease and starvation were wearing down the rebels inside the castle, and finally on 13 December 1266 the remnants of the garrison submitted.

They were allowed to leave with their arms, horses and harness. After 172 days of siege, only two days’ supply of food remained in the castle.

Legacy of the longest siege

The siege did not establish a lasting peace. The victorious royalists behaved vindictively, and the rebels quickly started up trouble elsewhere. When the civil war between Henry and his barons finally ended nearly a year later, it was the result of political compromise.

The siege was also ruinously expensive, leaving Henry so impoverished that he had to pawn the jewels from St Edward’s shrine in Westminster Abbey.

Experience a medieval siege this summer

You can experience the thrill of the siege for yourself with a summer of siege events at Kenilworth Castle. The castle is open daily throughout the summer from 10am – 6pm.

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