The Battle of Lens (20 August 1648) was a French victory under Louis II de Bourbon, Prince de Condé against the Spanish army under Archduke Leopold in the Thirty Years' War (1618–1648). It was the last major battle of the war. Lens is a fortified city in the historic region of Flanders, today a major city in the Pas-de-Calais region of northern France. The city had been captured by the French in 1647.