The Six Days Campaign (10–15 February 1814) was a final series of victories by the forces of Napoleon I of France as the Sixth Coalition closed in on Paris. As was said by his contemporary enemy, the Austrian general Johann von Nostitz-Rieneck, this campaign demonstrated Napoleon's tactical mastery "to the highest degree."
When the Napoleonic army was preparing to strike at Blücher's Russo-Prussian Army of Silesia, the latter's headquarters underestimated this threat. The Army of Silesia was stretched out on the march towards Paris. Its Russian corps commander Osten-Sacken had already made contact with the advanced Napoleon's units on 8 February, but did not report to Blücher, while its chief of staff Gneisenau made another blunder, namely, he believed that Napoleon's full movement from Villenauxe to Sézanne was only a reconnaissance after the leading French cavalrymen, who had come into view, retreated. A Russian officer arrived at Blücher's headquarters late on the 9th and reported to him and the staff that the army was under threat from the south, while on the night of the 10th intelligence discovered Napoleon himself already at Sézanne. Early on the 10th Napoleon attacked the central corps of the Army of Silesia, which was at Champaubert. Thus the Six Days Campaign began.