Next it was Blücher's turn. Leaving Mortier to pursue the fugitives of Sacken and Yorck along the Soissons road, Napoleon left Château-Thierry late at night on the 13th, following the mass of his troops to reinforce Marmont. That Marshal had yielded ground to Blücher's desperate efforts, but was standing at bay at Vauchamps, when Napoleon drew near to the scene of the unequal fight. Suddenly a mighty shout of "Vive l'Empereur" warned the assailants that they now had to do with Napoleon. Yet no precipitation weakened the Emperor's blow: not until his cavalry greatly outnumbered that of the allies did he begin the chief attack. Stoutly it was beaten off by the allied squares: but Drouot's artillery ploughed through their masses, while swarms of horsemen were ready to open out those ghastly furrows. There was nothing for it but retreat, and that across open country, where the charges and the pounding still went on. But nothing could break that stubborn infantry: animated by their leader, the Prussians and Russians plodded steadily eastwards, until, as darkness drew on, they found Grouchy's horse barring the road before Etoges. "Forward" was still the veteran's cry: and through the cavalry they cut their way: through hostile footmen that had stolen round to the village they also burst, and at last found shelter near Bergères. "Words fail me," wrote Colonel Hudson Lowe, "to express my admiration at their undaunted and manly behaviour." This gallant retreat shed lustre over the rank and file. But the sins of the commanders had cost the allies dear. In four days the army of Silesia lost fully 15,000 men, and its corps were driven far asunder by Napoleon's incursion. His brilliant moves and trenchant strokes astonished the world. With less than 30,000 men he had burst into Blücher's line of march, and scattered in flight 50,000 warriors advancing on Paris in full assurance of victory. It was not chance, but science, that gave him these successes. Acting from behind the screen of the Seine, he had thrown his small but undivided force against scattered portions of a superior force. It was the strategy of Lonato and Castiglione over again; and the enthusiasm of those days bade fair to revive.