Meanwhile the Prussian strategist, von Moltke, was carrying out a far more incisive plan of operations--that of sending three Prussian armies into the middle of Bohemia, and there forming a great mass which would sweep away all obstacles from the road to Vienna. This design received prompt and skilful execution. Saxony was quickly overrun, and the irruption of three great armies into Bohemia compelled the Austrians and their Saxon allies hurriedly to alter their plans. After suffering several reverses in the north of Bohemia, their chief array under Benedek barred the way of the two northern Prussian armies on the heights north of the town of Königgrätz. On the morning of July 3 the defenders long beat off all frontal attacks with heavy loss; but about 2 P.M. the Army of Silesia, under the Crown Prince Frederick of Prussia, after a forced march of twelve miles, threw itself on their right flank, where Benedek expected no very serious onset. After desperate fighting the Army of Silesia carried the village of Chlum in the heart of the Austrian position, and compelled Austrians and Saxons to a hurried retreat over the Elbe. In this the Austrian infantry was saved from destruction by the heroic stand made by the artillery. Even so, the allies lost more than 13,000 killed and wounded, 22,000 prisoners, and 187 guns[4]. [4] Sybel, _Die Begründung des deutschen Reiches_, vol. v. pp. 174-205; _Journals of Field Marshal Count von Blumenthal for 1866 and 1871_ (Eng. edit.), pp. 37-44. Königgrätz (or Sadowa, as it is often called) decided the whole campaign. The invaders now advanced rapidly towards Vienna, and at the town of Nikolsburg concluded the Preliminaries of Peace with Austria (July 26), whereupon a mandate came from Paris, bidding them stop. In fact, the Emperor of the French offered his intervention in a manner most threatening to the victors. He sought to detach Italy from the Prussian alliance by the offer of Venetia as a left-handed present from himself--an offer which the Italian Government subsequently refused. To understand how Napoleon III. came to change front and belie his earlier promises, one must look behind the scenes. Enough is already known to show that the Emperor's hand was forced by his Ministers and by the Parisian Press, probably also by the Empress Eugénie. Though desirous, apparently, of befriending Prussia, he had already yielded to their persistent pleas urging him to stay the growth of the Protestant Power of North Germany. On June 10, at the outbreak of the war, he secretly concluded a treaty with Austria, holding out to her the prospect of recovering the great province of Silesia (torn from her by Frederick the Great in 1740) in return for a magnanimous cession of Venetia to Italy. The news of Königgrätz led to a violent outburst of anti-Prussian feeling; but Napoleon refused to take action at once, when it might have been very effective.