The Battle of Lens is the last major military confrontation of the Thirty Years' War, contributing to the signing of the Peace of Westphalia in October that year.

The Battle of Lens was the last major battle of the Thirty Years' War (1618-1648). A French force commanded by Louis II de Bourbon, Prince de Condé defeated a Spanish army under Archduke Leopold Wilhelm. The battle cemented the reputation of Condé as one of the greatest generals of his age.

The Thirty Years' War, fought primarily in Central Europe between 1618 and 1648, was one of the most destructive conflicts in European history. An estimated 4.5 to 8 million soldiers and civilians died from battle, famine, or disease, while parts of Germany reported population declines of over 50%. Related conflicts include the Eighty Years' War, the War of the Mantuan Succession, the Franco-Spanish War, the Torstenson War, the Dutch-Portuguese War, and the Portuguese Restoration War.

The Peace of Westphalia is the collective name for two peace treaties signed in October 1648 in the Westphalian cities of Osnabrück and Münster. They ended the Thirty Years' War (1618–1648) and brought peace to the Holy Roman Empire, closing a calamitous period of European history that killed approximately eight million people. Holy Roman Emperor Ferdinand III, the kingdoms of France and Sweden, and their respective allies among the princes of the Holy Roman Empire, participated in the treaties.

August 20 is the 232nd day of the year in the Gregorian calendar; 133 days remain until the end of the year.