Napoleon replied by granting Caulaincourt full powers to do everything necessary "to keep the negotiations alive and save the capital." The Duke was unwilling to act upon so broad a basis and sent back once more for a specific detail of the Emperor's purposes.
Napoleon had his headquarters at Nogent, on the Seine, some leagues below Troyes, when the dispatch reached him on the evening of the 8th of February, and his counsellors urged him to make use of this, probably last, opportunity. He was prevailed upon to agree to abandon Belgium, the left of the Rhine, Italy and Piedmont, but in the night after the consultation, and before the ultimatum had his signature, he received information which caused him to change all his views. When Maret visited him with his dispatches ready for signing Napoleon was poring over his maps, tracing the route of Blucher on Paris. "Oh here you are!" he exclaimed as Maret entered, "but I am now thinking of something very different—I am beating Blucher on the map. He is advancing by the road to Montmirail; I will set out and beat him to-morrow. Should this movement prove as successful as I expect it will, the state of affairs will be entirely changed, and we shall then see what can be done."
The Emperor had learned that Blucher, instead of continuing his march down the Aube, and in communication with Schwartzenberg on the Seine, had transferred his whole army to the Marne, and was now advancing towards Paris by the Montmirail road.
The separation of their forces by the allies was a great blunder and the Emperor, who at once detected it, could not resist the temptation which it presented to make one warlike effort more. Napoleon, therefore, refused to sign the dispatch on the morning of the 9th and having left small forces to defend the bridge over the Seine at Nogent and at Bray, commenced his march, with the main body of his army, upon Sezanne, prepared for one of the most extraordinary and successful manoeuvres which has ever been recorded in the annals of war.
Forty miles were traversed over a most difficult country, usually considered impassable in winter,—ere the troops halted with the dark. Next morning the army moved again with equal alacrity, and at length debouched on the road by which Blucher's army was advancing, at Champaubert.
The central division was passing when Napoleon suddenly appeared at this point, and was altogether unable to resist his assault. They dispersed in confusion with great loss and fled towards the Marne. The General-in-chief, Ousouwieff, at the head of twelve regiments was completely routed. He was taken with 6,000 of his men, and the remainder were drowned in a swamp, or killed on the field of battle. Forty pieces of cannon, and all the ammunition and baggage were left in the power of the victor. Napoleon had now interposed his army between the advanced guard of the Silesian army, commanded by Sacken, and the rear commanded by Blucher himself.
The van of the same army turned, on hearing the cannonade of Champaubert, and countermarched with the view of supporting Alsusieff only to share the fate of the centre, and were put to flight after the loss of one-fourth of the division.
Now it was Blucher's turn to be beaten. Napoleon mounted his horse at midnight on the 13th and came up with him at Montmirail. At 8 o'clock in the morning the shouting of the soldiers announced the presence of the Emperor. Blucher would gladly have declined battle, but it was out of his power. He was conquered but retreated with great skill and courage. After many hours of hard fighting his retreat became a flight. Blucher was frequently obliged to defend himself with his sabre during the day, surrounded by his staff, and chiefly owed his escape to the darkness of the night.