While Mack expected the approach of the French upon his front, Buonaparte had formed the daring resolution to turn the flank of the Austrian general, cut him off from his country and his resources, and reduce him to the necessity, either of surrender, or of giving battle without a hope of success. To execute this great conception, the French army was parted into six grand divisions. That of Bernadotte, evacuating Hanover, which it had hitherto occupied, and traversing Hesse, seemed as if about to unite itself to the main army, which had now reached the Rhine on all points. But its real destination was soon determined, when, turning towards the left, Bernadotte ascended the river Maine, and at Wurtzburg formed a junction with the elector of Bavaria, who, with the troops which had followed him into Franconia, immediately declared for the French cause. The elector of Wirtemberg and the Duke of Baden followed the same line of politics; and thus Austria had arrayed against her those very German princes, whom a moderate conduct towards Bavaria might perhaps have rendered neutral; France, at the outset of the contest, scarce having the power to compel them to join her standard. The other five columns of French troops, under Ney, Soult, Davoust, Lannes, and Marmont, crossed the Rhine at different points, and entered Germany to the northward of Mack's position; while Murat, who made his passage at Kehl, approaching the Black Forest, manœuvred in such a manner as to confirm Mack in his belief that the main attack was to come from that quarter. But the direction of all the other divisions intimated that it was the object of the French Emperor to move round the right wing of the Austrians, by keeping on the north or left side of the Danube, and then by crossing that river, to put themselves in the rear of Mack's army, and interpose betwixt him and Vienna. For this purpose, Soult, who had crossed at Spires, directed his march upon Augsburg; while, to interrupt the communication betwixt that city and Ulm, the Austrian headquarters, Murat and Lannes had advanced to Wertingen, where a smart action took place. The Austrians lost all their cannon, and it was said four thousand men--an ominous commencement of the campaign. The action would have been termed a battle, had the armies been on a smaller scale; but where such great numbers were engaged on either side, it did not rank much above a skirmish.[128] With the same purpose of disquieting Mack in his headquarters, and preventing him from attending to what passed on his left wing and rear, Ney, who advanced from Stutgard, attacked the bridges over the Danube at Guntzburg, which were gallantly but fruitlessly defended by the Archduke Ferdinand, who had advanced from Ulm to that place. The archduke lost many guns, and nearly three thousand men.[129]