Philip VI Declares War on Edward III: The Beginning of the Hundred Years’ War (1337)

By 1337, tensions between Philip VI of France and Edward III of England had reached a breaking point. The immediate cause was Philip’s decision to confiscate the Duchy of Aquitaine (Gascony), triggering the Hundred Years’ War (1337–1453).

Philip VI’s Refusal to Negotiate (April 1337)

• Philip was invited to meet with an English delegation at the end of April 1337, but he refused, signaling that diplomatic efforts had collapsed.
• On April 30, 1337, the arrière-ban, or royal call to arms, was proclaimed throughout France, preparing the kingdom for war against England.

Philip’s Great Council and the Confiscation of Aquitaine (May 1337)

• In May 1337, Philip VI convened his Great Council in Paris to discuss the worsening crisis with England.
• The council unanimously agreed that the Duchy of Aquitaine (effectively Gascony) should be seized.
• Philip justified this move by accusing Edward III of violating his feudal obligations as vassal and for providing shelter to the king’s "mortal enemy," Robert III of Artois.

The Final Break and the Road to War

• By taking Gascony into his own hands, Philip VI directly challenged English sovereignty over its last remaining continental possession.
• Edward III saw this as a clear act of aggression, and by autumn 1337, he had begun preparing for war against France.
• In October 1337, Edward formally revoked his homage to Philip VI, effectively declaring himself independent of French suzerainty.

The Start of the Hundred Years’ War

• The confiscation of Aquitaine in 1337 marked the beginning of open hostilities between England and France, leading to one of the longest and most consequential wars in medieval Europe.
• Though rooted in feudal disputes, the conflict evolved into a struggle for the French crown, particularly after Edward III formally claimed the French throne in 1340.

Philip VI’s decision in 1337 to seize Gascony was the final act that pushed England and France into full-scale war, ushering in a new era of military and political conflict that would last for more than a century.