Siege = To surround a fortified area (such as a castle) with military forces to bring about its surrender
With dreams of regaining Normandy, King John had imposed some unpopular taxes for his military expeditions against Philip Augustus of France. This included demanding enormous fees for a baronial heir to inherit property. His relationship with his barons thus already strained, the King infuriated them further by choosing a foreigner, Peter des Roches the Bishop of Winchester, to take over while he was away.
On his return in 1214, there were still barons who were willing to negotiate, but there were also rebels who would eventually rise against the King. The Magna Carta of political and civil liberties (which outlawed some of the King’s methods of taxation) was drawn up.
To buy some time, the King signed it at Runnymede in 1215. However, he had no intention of allowing it to stand and wrote immediately to the Pope to have the charter annulled. This sparked a civil war and the barons invited Prince Louis of France to become king of England. The French prince landed and marched on London. King John was forced to retreat. He fell ill and died in Oct 1216, leaving his nine year old son Henry III as king.
Maybe the attackers halted in their march to wonder at the double-moated fortress that was their target. Beyond the counterscarp bank to the North and East at Berkhamsted Castle was a further bank backed by seven earth bastions. It is said that these were built by the attacking forces, but it is more likely that they were part of King John’s restoration efforts.
It seems likely that heavy siege engines were constructed at the site, rather than being transported. Most siege engines, such as the mangonel, were capable of throwing a stone of 300 lbs or more a distance of at least 150 metres.
In Dec 1216, Berkhamsted Castle was besieged by Prince Louis of France. It is likely that the constable at the castle was aware of the approach of a hostile force of French mercenaries. He will have hastily arranged for plentiful food supplies to be brought in: bread, cheese, eggs and meat. Hopefully, he would have sent women and children out of harm’s way, if only to preserve the food and drink supplies for fighting men. Wells in the bailey and on the motte provided plentiful water and they would have hunkered down, ready for the attack.
It is said that Prince Louis introduced a new and even more terrifying siege engine to England and used it at Berkhamsted—the trebuchet.
This worked like a catapult, with a large stone being placed in a sling at the end of the long beam. In the early days, people exerted downward pull on the short end of the beam to flip up the longer end. As designs became more sophisticated, a counterweight was used to provide the downward pull. It was by trial and error that the trajectory and distance were worked out. The effect would have been devastating on the walls and towers of the castle and terrifying for those cowering within.
King Henry III ordered his constable at the castle to surrender after two weeks on humanitarian grounds. Hopefully this was not in response to a common practice in those days of catapulting dead animals into the castle grounds in the hope of spreading disease.