At the beginning of August 1805, Napoleon gave up his plan for invading Great Britain across the English Channel. Instead, he decided to move his army from the channel coast to south Germany to smash the Austrian army. The Aulic Council thought Napoleon would strike in Italy again. Thanks to an elaborate spy network, Napoleon was aware that the Austrians deployed their largest army in Italy. The emperor desired that Archduke Charles' army not be allowed to influence events in southern Germany. Napoleon ordered 210,000 French troops be launched eastwards from the camps of Boulogne and would envelop General Mack's exposed Austrian army if it kept marching towards the Black Forest. Meanwhile, Marshal Murat would conduct cavalry screens across the Black Forest to fool the Austrians into thinking that the French were advancing on a direct west–east axis. He hoped to be at the Austrian capital of Vienna in November, before the Russian army appeared on the scene.