The French Seizure of Brittany and the…

The French Seizure of Brittany and the Exile of Duke John IV (1373)

By 1373, Brittany had become heavily indebted to King Edward III of England, further entrenching English influence in the duchy. Duke John IV’s administration was largely controlled by English advisors, including Thomas Melbourne, the Treasurer and Receiver General of the Duchy. This foreign domination, combined with widespread discontent over the implementation of a permanent ducal tax (the hearth tax), led to growing opposition from the Breton nobility, particularly from Olivier de Clisson.

Duke John IV’s Continued Alliance with England

• Facing increasing pressure from French-backed factions in Brittany, John IV chose to reaffirm his alliance with England, signing a new treaty with Edward III.
• To justify this to France, John IV claimed he had no choice but to host English troops in order to counter Olivier de Clisson’s growing influence in Brittany.
• English garrisons were stationed in key strategic locations, including:
  • Derval
  • Rougé
  • Brest
  • Saint-Mathieu

Charles V’s Response: The French Invasion of Brittany (March 1373)

• In response to John IV’s continued English alliance, King Charles V of France ordered his Constable, Bertrand du Guesclin, to seize the Duchy of Brittany on March 1, 1373.
• To ensure the support of Olivier de Clisson, Charles granted him the lordship of Guillac, further securing Clisson’s loyalty to the French Crown.
• Du Guesclin and Clisson launched a propaganda campaign, seeking to discredit John IV and turn the Breton nobility against him.

Duke John IV’s Fall and Exile (April 28, 1373)

• The French offensive was swift and effective, with much of the Breton nobility turning against John IV due to:
  • Opposition to English rule in Brittany.
  • Discontent over excessive taxation.
• With his support collapsing, John IV was forced to flee the duchy.
• On April 28, 1373, he crossed the English Channel into exile, taking refuge in England under Edward III’s protection.

Impact of the French Takeover

• With John IV in exile, Brittany was effectively under French control, with du Guesclin and Clisson consolidating power.
• The defeat of John IV marked a significant shift in Breton politics, strengthening French authority in the duchy.
• However, John IV’s exile did not end the conflict, as he would later attempt to reclaim his duchy with English support.

The French invasion of Brittany in 1373 and the exile of Duke John IV marked a major turning point, as Charles V’s military strategy continued to weaken English influence in France, setting the stage for further conflicts over Breton sovereignty.