In the weeks following Napoleon’s monumental defeat at the battle of Leipzig, Coalition forces failed to catch his army as it retreated through Germany and across the Rhine River. Regardless, the Allies decided 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. By the end of January, Holland and Belgium had fallen, and two Allied armies stood at the Marne and Aube Rivers ready to march on Paris. This circumstance forced Bonaparte to leave his capital and finally assume personal command of the army. After ferocious fighting in February, Napoleon made a daring gamble. To threaten the Coalition’s lifeline across the Rhine, he decided to maneuver against the rear of the main Allied army in the hope of forcing it to withdraw from France. With the French emperor between them and the Rhine River, the Allies took advantage of the open roads to reach Paris. The city surrendered on 31 March. Six days later, Napoleon abdicated unconditionally.