Edward III, King of England, had ascended to the throne, vacated by his overthrown and imprisoned father Edward II, in January 1327. Edward III as a descendant of William I (also known as ‘the conqueror’) had inherited the French titles of Duke of Guyenne and Count of Ponthieu, in addition to being the son of Isabella of France, the sister of the heirless King Charles IV of France. In 1328, when Charles IV died, Edward considered himself to have a legitimate claim on the French throne. The other major claimant was Phillip of Valois, a cousin of Charles IV, who as a descendant through the male line had the stronger claim according to ancient Salic law. However Charles had left a pregnant widow, and the possibility of a male heir, so Phillip assumed the role of regent until the child was born. He was crowned King Phillip VI of France at Reims in May 1328 after the widow of Charles IV had given birth to a daughter.
King Edward at first seemed to accept Phillip’s accession to the throne of France, and instead focused on making a peace treaty with Scotland in order to avoid the possibility of an invasion from two sides. However, after years of simmering tension caused by disputes over the duchy of Aquitaine and other territories in South- West France, which were traditionally held by the English Monarch. For which he was obligated to pay homage to the French King, in accordance with the treaty made between Henry III of England and Louis IX of France in 1259. Edward did pay homage twice, once in 1329, and again in 1331. However, tension had developed over the legal position of the King, and his rights as Duke of Aquitaine, and which lands the French were to control. By 1333 the opinion in Aquitaine was generally in favour of English rule.
Edward had further angered Phillip by offering refuge to Robert III of Artois, a French noble who had been one of Phillip’s closest advisors until a dispute over the County of Artois, when Robert had used a forgery attesting to the will of his father in order to obtain the title and lands he felt were his by right. Having lost his inheritance, he had fled the country to avoid execution, and had arrived in England with a wealth of information on the French court. In 1336 Phillip VI officially demanded the extradition of Robert and by May 1337 had declared Edward III to have forfeited Aquitaine by offering shelter to an enemy of France. In retaliation Edward decided to press his claim to the French throne, attempting to rally support by sending an embassy to Flanders, and the Low Countries. The Duke of Flanders, Louis I was an avid supporter of French Policy, and had, together with his allies, prevented an invasion of France from progressing as Edward had planned. The Duke had placed his half-brother Guy “The Bastard of Flanders” in command of the Garrison at Sluys, close to what is now the border of The Netherlands and Belgium. In those times the two countries were known as Zeeland and Flanders.
The Island of Cadsand, across the waters of the Zwin Estuary was the location for the first battle of the Hundred Years War. Although a fairly minor engagement, it was a decisive victory for the English. Under the command of Sir Walter Manny, around 3700 men had made raids on the Island in order to draw out the Flemish army. On November 9th Sir Guy, Bastard of Flanders (illegitimate son of Louis, Count of Nevers and half-brother of Louis I), the Commander of the garrison at Sluys, crossed the estuary with several thousand men in order to confront the English. Sir Walter had been prepared for this, and had drawn his men up in a good defensive position; they were able to beat back the advancing Flemish with relative ease, possibly with the use of the Longbow, although unfortunately no detailed accounts of the battle survive. Sir Guy was captured, along with many of his men, only a few were able to retreat across the river to the garrison, resulting in an almost total loss for the Flemish army. The English were victorious, with minimal casualties. The battle was seemingly simply a show of force and a plan to improve morale amongst King Edward’s forces and allies. The Island was left to its surviving inhabitants.
The actions of Louis I, count of Flanders resulted in a boycott of the English wool trade, upon which the Flemish depended; this led to an uprising under the political leader Jacob Van Artevelde, which forced Louis to flee to France, leaving his lands for good. He was killed at the Battle of Crecy in 1346. In 1340 Flanders aligned with England, recognised Edward III as rightful Sovereign of France and Overlord of Flanders, and Flemish trade and industry flourished. Artevelde served as captain general of Ghent until his death in 1345.