Harold Godwinson’s Campaign with William of Normandy Against Conan II of Brittany (1064–1065)

Following his capture and transfer to Duke William of Normandy in 1064, Harold Godwinson reportedly accompanied William on a military campaign against Conan II, Duke of Brittany. This campaign was part of William’s ongoing conflict with Brittany, which had remained a rival power to Normandy.

The Norman-Breton Conflict

• Conan II of Brittany, who had come to power in 1057, had long been a rival of William of Normandy.
• By 1064, tensions between Normandy and Brittany had escalated into open conflict.
• Duke William led an invasion into Brittany, aiming to assert Norman dominance over the region.
• Harold joined William’s forces, possibly as a way to demonstrate his loyalty while still in Norman custody.

Harold’s Role in the Campaign

• According to later Norman sources, Harold fought alongside William’s army, participating in raids and siegesagainst Breton forces.
• As they advanced into Brittany, the Normans crossed past the fortified abbey of Mont Saint-Michel, a key strategic landmark on the Norman-Breton border.
• During the crossing of dangerous tidal flats, two Norman soldiers became trapped in quicksand.
• Harold reportedly saved them, an event that was later recorded in Norman sources, likely to emphasize Harold’s military prowess and bravery.

Aftermath and Consequences

• The Norman campaign was successful, and Conan II was forced to retreat.
• While Harold’s participation may have strengthened his relationship with William, it remains uncertain whether he was acting of his own free will or under obligation.
• The campaign further solidified William’s control over Normandy’s western frontier, weakening Brittany as a regional power.

Significance of Harold’s Participation

• Harold’s presence in William’s military campaign was later used as propaganda by the Normans, reinforcing the idea that Harold had sworn loyalty to William.
• His rescue of Norman soldiers may have been recorded to highlight his military competence, demonstrating that he was respected even among the Normans.
• The campaign likely played a role in Harold’s eventual departure from Normandy, as it may have helped secure his release.

While Harold’s participation in the Norman-Breton war remains debated, it was an important episode in the lead-up to the Norman Conquest, as it reinforced William’s belief in Harold’s loyalty—whether real or imagined.