In October 1813, Emperor Napoleon I entrenched himself in the Saxon city of Leipzig and prepared for a showdown with his enemies for control of Germany. Four Allied armies eventually surrounded the French during the epic Battle of Nations. Napoleon held Leipzig for four days until exhausting his ammunition supply. He then exploited a gap in the Allied lines to lead 70,000 of his soldiers out of the beleaguered city. In the weeks that followed, the Allied armies failed to catch the French army as it retreated to the Rhine River. After Napoleon escaped across the Rhine in early November, the Allies held a great council of war at Frankfurt-am-Main. These deliberations ended with the decision to launch a comprehensive invasion of France from the North Sea to Switzerland.

In late November, 40,000 Prussian, British, and Russian troops invaded Holland. One month later, 200,000 Allied soldiers crossed the upper Rhine to invade Alsace, Switzerland, and Franche-Comté. Shortly after, on New Year's Day, an additional 75,000 men crossed the middle Rhine and drove through Lorraine toward the fortress of Metz. To stop the Allied masses, Napoleon spread approximately 56,000 tired troops in a thin cordon along the length of the Rhine River. Napoleon himself remained at Paris during the Allied invasion to direct a mobilization that he expected would produce a new army of almost 400,000 men.