Bernadotte advanced from Hanover, with the troops which had occupied that electorate, towards Wurtzburg, where the Bavarian army lay ready to join its strength to his; five divisions of the great force lately assembled on the coasts of Normandy, under the orders of Davoust, Ney, Soult, Marmont, and Vandamme, crossed the Rhine at different points, all to the northward of Mack's position; while a sixth, under Murat, passing at Kehl, manoeuvred in such a manner as to withdraw the Austrian's attention from these movements, and to strengthen him in his belief that Napoleon and all his army were coming against him through the Black Forest in his front.
The consequence of Buonaparte's combinations was, that while Mack lay expecting to be assaulted in front of Ulm, the great body of the French army advanced into the heart of Germany, by the left side of the Danube, and then, throwing themselves across that river, took ground in his rear, interrupting his communication with Vienna, and isolating him.

In order that Bernadotte and the Bavarians might have a part in this great manoeuvre, it was necessary that they should disregard the neutrality of the Prussian territories of Anspach and Bareuth; and Napoleon, well aware of the real sentiments of the court of Berlin, did not hesitate to adopt this course.

Prussia remonstrated indignantly, but still held back from proclaiming war; and Napoleon cared little for such impediments as mere diplomacy could throw in the way of his campaign.

He did not, however, effect his purpose of taking up a position in the rear of Mack without resistance.

On the contrary, at various places, at Wertenghen, Guntzburg, Memingen, and Elchingen, severe skirmishes occurred with different divisions of the Austrian army, in all of which the French had the advantage.