Relief of Thionville

Coordinated French and Dutch attacks on the Spanish Netherlands in May 1638 forced Spain to abandon a planned offensive in Artois. Despite fighting on two fronts simultaneously, the Spanish Army of Flanders managed to defeat the Dutch at Kallo in June while Thomas Francis, Prince of Carignano and the Imperial auxiliary corps under Ottavio Piccolomini lifted the French Siege of Saint-Omer in July. France renewed his attacks in 1639 by besieging Hesdin with 14,000 men under La Meilleraye supported by additional troops under Châtillon. The Marquis de Feuquieres was ordered to capture the principal fortress of Thionville in the Duchy of Luxemburg. Control of Thionville secured access to the southern Spanish Netherlands and the Moselle Valley, it also enabled the Imperials to support their Spanish allies by threatening the French flank.

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