information:extraction, linguistic:paraphrasing
Dispute over Guyenne: a problem of sovereignty

Tensions between the French and English monarchies can be traced back to the 1066 Norman Conquest of England, in which the English throne was seized by the Duke of Normandy, a vassal of the King of France. As a result, the crown of England was held by a succession of nobles who already owned lands in France, which put them among the most influential subjects of the French king, as they could now draw upon the economic power of England to enforce their interests in the mainland. To the kings of France, this threatened their royal authority, and so they would constantly try to undermine English rule in France, while the English monarchs would struggle to protect and expand their lands. This clash of interests was the root cause of much of the conflict between the French and English monarchies throughout the medieval era.

The Anglo-Norman dynasty that had ruled England since the Norman conquest of 1066 was brought to an end when Henry, the son of Geoffrey of Anjou and Empress Matilda, and great-grandson of William the Conqueror, became the first of the Angevin kings of England in 1154 as Henry II. The Angevin kings ruled over what was later known as the Angevin Empire, which included more French territory than that under the kings of France. The Angevins still owed homage to the French king for these territories. From the 11th century, the Angevins had autonomy within their French domains, neutralizing the issue.

King John of England inherited the Angevin domains from his brother Richard I. However, Philip II of France acted decisively to exploit the weaknesses of John, both legally and militarily, and by 1204 had succeeded in taking control of much of the Angevin continental possessions. Following John's reign, the Battle of Bouvines (1214), the Saintonge War (1242), and finally the War of Saint-Sardos (1324), the English king's holdings on the continent, as Duke of Aquitaine, were limited roughly to provinces in Gascony.

The dispute over Guyenne is even more important than the dynastic question in explaining the outbreak of the war. Guyenne posed a significant problem to the kings of France and England: Edward III was a vassal of Philip VI of France because of his French possessions and was required to recognize the suzerainty of the King of France over them. In practical terms, a judgment in Guyenne might be subject to an appeal to the French royal court. The King of France had the power to revoke all legal decisions made by the King of England in Aquitaine, which was unacceptable to the English. Therefore, sovereignty over Guyenne was a latent conflict between the two monarchies for several generations.

During the War of Saint-Sardos, Charles of Valois, father of Philip VI, invaded Aquitaine on behalf of Charles IV and conquered the duchy after a local insurrection, which the French believed had been incited by Edward II of England. Charles IV grudgingly agreed to return this territory in 1325. Edward II had to compromise to recover his duchy: he sent his son, the future Edward III, to pay homage.

The King of France agreed to restore Guyenne, minus Agen, but the French delayed the return of the lands, which helped Philip VI. On 6 June 1329, Edward III finally paid homage to the King of France. However, at the ceremony, Philip VI had it recorded that the homage was not due to the fiefs detached from the duchy of Guyenne by Charles IV (especially Agen). For Edward, the homage did not imply the renunciation of his claim to the extorted lands.