The Battle of Lens (August 20, 1648) was a French victory under Louis II of Bourbon, Prince of Condé against the Spanish army under Archduke Leopold Wilhelm in the Thirty Years' War (1618-1648). It was the last major battle of the war and a French victory. The battle cemented Condé's reputation as one of the greatest generals of his age. In the four years following the decisive French victory at Rocroi against the Spanish Army of Flanders, the French captured dozens of towns in northern France and Spanish Holland. Archduke Leopold Wilhelm was appointed governor of the Spanish Holland in 1647 to strengthen the Spanish-Habsburg alliance with Austria and began a major controversy in the same year. The Spanish army first found success in recapturing the fortresses of Armentières, Comines and Landrecies. The Prince de Condé was recalled from a failed campaign in Catalonia against the Spanish commander and appointed commander of the 16.000-strong French army, opposite the Spanish army of the Archduke and General Jean de Beck, Governor of Luxembourg. Condé captured Ypres, but then the Spanish-German force of 18.000 besieged Lens.