The Siege of Gerberoi and William the Conqueror’s Humiliation (January 1079)

By January 1079, William the Conqueror had grown increasingly frustrated with his rebellious eldest son, Robert Curthose, who, with the support of King Philip I of France, had fortified himself in Gerberoi Castle. Determined to crush the revolt, William launched a three-week siege of Gerberoi. However, in an unexpected counterattack, Robert’s forces routed the besiegers, and in the ensuing battle, Robert personally unhorsed his father, delivering William one of the most humiliating defeats of his reign.

The Siege of Gerberoi (January 1079)

• William’s besieging army set up camp around Gerberoi, aiming to starve the defenders into submission.
• The castle’s defenders, led by Robert Curthose and his knights, with French reinforcements, held firm against William’s forces.
• For three weeks, the Normans maintained the siege, but failed to breach the defenses.

The Counterattack and William’s Humiliation

• In a daring sally, Robert and his men launched a surprise attack on the Norman besiegers, catching them off guard.
• In the ensuing chaos, Robert encountered his father in battle and personally unhorsed him, knocking the King of England and Duke of Normandy to the ground.
• William was only saved from death by a loyal English knight, who intervened just in time.

Aftermath: William’s Rage and the End of the Siege

• Humiliated by his son’s victory, William cursed Robert, publicly disowning him in the heat of battle.
• He then abandoned the siege and retreated to Rouen, marking one of the few battlefield defeats in his career.
• This clash at Gerberoi proved Robert’s military capability, earning him respect among his allies in France and Flanders.

Consequences and Significance

• Robert’s victory at Gerberoi strengthened his position, proving that he could hold his own against his formidable father.
• The defeat weakened William’s authority, particularly among his continental vassals, showing that his rule over Normandy was not absolute.
• This father-son conflict would continue to divide the Norman dynasty, ultimately contributing to the eventual loss of Normandy to England’s enemies.

The Siege of Gerberoi (1079) marked one of the lowest points of William the Conqueror’s reign, demonstrating the growing rift between him and his eldest son, a conflict that would shape the fate of Normandy and England in the years to come.