With one French Army (under Bazaine) bottled up in Metz, Emperor Napoleon III took personal command of MacMahon's Army and marched it from Chalons-sur-Marne to attempt to relieve it. Von Moltke, however, sent his new Army of the Meuse to intercept, which caused the French to withdraw to Sedan, where they were surrounded but the Prussian 3rd Army and Army of the Meuse.
The Prussians battered the French with devastating artillery and when an attempt to break out from the Prussian encirclement failed the Emperor, along with more than 100,000 men surrendered. It was the end of Louis Napoleon, and one of the worst defeats in French history.

North of the town of Sedan, France. (France)