How did the Hundred Years’ War divide the count of Flanders from the Flemish towns?

The Hundred Years’ War (which began c. 1337) created a significant political and economic rift between the count of Flanders and the major Flemish towns, primarily due to conflicting foreign policy interests.12

• Conflicting Allegiances: The count of Flanders, Louis I, sought the protection of the French king and sided with France during the conflict. Conversely, the Flemish towns—particularly Ghent, Brugge, and Ypres—relied heavily on the import of English wool for their massive textile industries and consequently aligned themselves with England.12
• Shift in Power: As the count fled to France for protection, he effectively left the administration of the county in the hands of these three major cities, which functioned essentially as city-states.1
• Economic Necessity: The towns’ prosperity was so intrinsically tied to English wool that they prioritized their economic survival over the count’s political loyalty to the French crown, leading to open defiance and, at times, direct revolt against the count’s authority.12