French Invasion of Flanders (1635)

Timeline

1. 1635Flanders border · Spanish NetherlandsAfter France declared war, the two countries formed a joint military force under the February 1635 Franco-Dutch treaty. French troops under Marshal Châtillon and the Prince of Condé crossed into the Spanish Netherlands' Flanders, forming a pincer with Dutch forces under Prince Frederick Henry of Orange; the allies planned to outflank Spain's core defenses in the Low Countries and drive on Brussels.
2. 1635Tirlemont (Tienen) · Spanish NetherlandsThe Franco-Dutch allied forces advanced rapidly, capturing and sacking Tirlemont (modern Tienen, Belgium) and pushing into the Spanish Netherlands' interior. The allies operated in Brussels' outskirts, forcing the Spanish governor Cardinal-Infante Ferdinand to urgently mobilize the city's defense. However, serious coordination problems arose between the two allied columns, and the missed timing cost them the best opportunity to attack.
3. 1635Flanders · Spanish NetherlandsIn the summer heat, dysentery and plague spread widely through the Franco-Dutch allied army, severely weakening its fighting power. Overextended supply lines caused shortages and heavy French losses. Unable to maintain the threat to Brussels, the allies withdrew in batches to their own territory. Though the invasion failed to achieve its strategic goals, it demonstrated Franco-Dutch military resolve to Spain and laid the basis for subsequent sustained offensives in the Spanish Netherlands.