800 years ago an invading army swept through Hertfordshire in the name of the French king. As Hertford Castle marks the seige by the French this month, Michael Long looks at how two key fortifications and the surrounding lands were attacked with a ferocity unimagined by its defenders

Great British Life: Manuscript depicting Philip II of France taking the keys to a castleManuscript depicting Philip II of France taking the keys to a castle (Image: wikimedia)

In 1216 the French came to Hertford; not in friendship but as an invading army under the command of the Dauphin, Prince Louis, the eldest son of the French King. For nearly four weeks in the cold November rains of 1216, his forces besieged Hertford Castle and ravaged the local area.

The French invasion of England and the laying siege to the castle was the culmination of an ongoing struggle between the Plantagenet kings of England, who were also rulers of a vast empire in France, and their enemy, King Phillip II of France. But by 1216, the Plantagenet hold on its empire was waning. King John had abandoned his French lands and fled to England where his barons were in open revolt against his rule. His death of dysentery in October that year brought his nine-year-old son Henry III to the throne under the guiding hand of William Marshal, Earl of Pembroke: England was vulnerable and Prince Louis sought to exploit it.

King John - who like his father Henry II and older brother King Richard, was to all intents and purposes, French not English - was a weak leader and did not have the military skill of his father or brother. In 16 years, he had lost the Plantagenet empire in France, imposed punitive taxes at home, offended the church and alienated his barons. This had plunged England into civil war resulting in the barons forcing John to accept the Magna Carta peace settlement of the previous year. Almost immediately John reneged on the agreement and the war continued.

Great British Life: The 14th century postern gate built into the 12th century flint and stone wall that encircled the castleThe 14th century postern gate built into the 12th century flint and stone wall that encircled the castle (Image: alamy)

During the baron’s revolt against John, Hertford Castle was held by Robert Fitzwalter, one of the leading nobles opposed to the king and a prime mover in drawing up Magna Carta. But in the civil war, Fitzwalter was forced to flee to France and the king repossessed the castle. In France, Fitzwalter was one of the rebel lords who encouraged the 28-year-old Dauphin to invade England and take the crown. When Louis arrived at Hertford in November with an invasion force of 3,000 men borne to England on 800 ships, two-thirds of English barons backed his claim to the English throne.

Hertford was a favoured noble residence and strategically important, sited at the confluence of four river valleys. An original wooden castle had been built beside the river Lea by King Edward the Elder in 911, and following the Norman conquest in 1066, its defences were reconstructed with a high conical mound, the motte, and an oval-shaped lower area, the bailey. In 1170, under the Plantagenet King Henry II, the defences of Hertford Castle were upgraded again with a deep ditch and stone and flint walls – still visible today. By 1216 Hertford was an impressive fortress and one that would be difficult to capture.

The town had grown with the castle’s importance. Trade flourished as merchants, tanners, bakers, butchers, dyers, smiths, leather workers, carpenters and masons established themselves around the castle. But ertford in 1216 was dirty, stinking and infested with vermin. Sewage went into the Lea, which was the primary source of drinking water. The banks beyond the river were marshes; little wonder disease was endemic.

Great British Life: Medieval cutting-edge weaponry - the giant rock hurling mangonelMedieval cutting-edge weaponry - the giant rock hurling mangonel (Image: wikimedia)

Since his invasion, Louis had laid siege and taken some of England’s key castles and towns including Rochester and Canterbury. By November, he had moved his army to Hertford. Historians are unsure as to whether he brought his massive siege engines with him or assembled new ones using the abundant supply of wood in the forests surrounding the town. Few of those looking on from the battlements would have come across the siege weapons that now faced them. The mangonel hurled massive rocks at a flat trajectory to break a stone wall. Repeated attacks would cause the wall to fail and the resulting breach would be stormed. The trebuchet worked by counterweights throwing rocks of up to 150kg on a high arc to come crashing down on fortifications and defenders.

The besiegers could try to starve out the defenders, but Louis - eager to continue the destructive speed of his campaign - deployed his powerful siege engines to attack the walls.

What of the people of the town while Louis besieged the castle? All those who could would have fled, most into the castle. Hertford’s undefended settlement outside the walls would have been stripped by Louis’ army all that could be eaten or was of value, and buildings burned. Further off villages would have witnessed French foraging parties seizing food and animals. Given that Louis had 3,000 men and winter was taking hold this would have affected communities within an estimated 20-mile radius. Louis’s soldiers engaged in ‘ravaging’ – a policy of terror towards non-combatants; killing, raping, stealing, burning and torturing. There was no chivalry here.

The siege began on November 12. The castle defenders under the command of Walter de Godardville inflicted heavy casualties on the French attackers but could do nothing to stem the effects of the siege weapons.

By December 6, having held out for 25 days, the castle surrendered, possibly on orders from William Marshal. As part of the surrender, the defenders were allowed to leave unmolested, taking with them their weapons and horses.

Hertford captured, Fitzwalter expected to receive it back from Louis, but Louis refused saying, such a fortress should not be given to a baron, who had betrayed his king.

Despite his siege engines, it took Louis nearly a month to take Hertford Castle, giving renewed hope to supporters of young King Henry and showing that a swift French victory wasn’t inevitable.

When Louis moved on to his next target, Berkhamsted Castle which controlled the narrow valley through the Chilterns, its commander refused to recognise the Hertford agreement resulting in another siege. The siege of Berkhamsted Castle lasted just two weeks before it too surrendered.

Louis headed to London but the following year was defeated by William Marshal at the Battle of Lincoln, forcing him to retreat to France and abandon his claim to the English Crown.

With this, Hertford and Berkhamsted were abandoned by the invaders and once more came under English control.