As the divisions of Wurmser's army began to arrive on the Tyrolese district of Trent, where the Austrian general had fixed his head-quarters, Buonaparte became urgent, either that reinforcements should be despatched to him from France, or that the armies of the Rhine should make such a movement in advance towards the point where they might co-operate with him, as had been agreed upon at arranging the original plan of the campaign. But he obtained no succours; and though the campaign on the Rhine commenced, as we have seen, in the month of June, yet that period was too late to afford any diversion in favour of Napoleon, Wurmser and his whole reinforcements being already either by that time arrived, or on the point of arriving, at the place where they were to commence operations against the French army of Italy.169
The thunder-cloud which had been so long blackening on the mountains of the Tyrol, seemed now about to discharge its fury. Wurmser, having under his command perhaps eighty thousand men, was about to march from Trent against the French, whose forces, amounting to scarce half so many, were partly engaged in the siege of Mantua, and partly dispersed in the towns and villages on the Adige and Chiese, for covering the division of Serrurier, which carried on the siege. The Austrian veteran, confident in his numbers, was only anxious so to regulate his advance, as to derive the most conclusive consequences from the victory which he doubted not to obtain. With an imprudence which the misfortunes of Beaulieu ought to have warned him against, he endeavoured to occupy with the divisions of his army so large an extent of country, as rendered it very difficult for them to maintain their communications with each other. This was particularly the case with his right wing under Quasdonowich, the Prince of Reuss, and General Ocskay, who were detached down the valley of the river Chiese, with orders to direct their march on Brescia. This division was destined to occupy Brescia, and cut off the retreat of the French in the direction of Milan. The left wing of Wurmser's army, under Melas, was to descend the Adige by both banks at once, and manœuvre on Verona, while the centre, commanded by the Austrian field-marshal in person, was to march southward by the left bank of the lago di Guarda, take possession of Peschiera, which the French occupied, and, descending the Mincio, relieve the siege of Mantua. There was this radical error in the Austrian plan, that, by sending the right wing by the valley of Chiese, Wurmser placed the broad lake of Guarda, occupied by a French flotilla, between that division and the rest of his army, and of course made it impossible for the centre and left to support Quasdonowich, or even to have intelligence of his motions or his fate.170
The active invention of Buonaparte, sure as he was to be seconded by the zeal and rapidity of the French army, speedily devised the means to draw advantage from this dislocation of the Austrian forces. He resolved not to await the arrival of Wurmser and Melas, but, concentrating his whole strength, to march into the valley of Chiese, and avail himself of the local superiority thus obtained, to attack and overpower the Austrian division left under Quasdonowich, who was advancing on Brescia, down the eastern side of the lake. For this purpose one great sacrifice was necessary. The plan inevitably involved the raising of the siege of Mantua. Napoleon did not hesitate to relinquish this great object, at whatever loss, as it was his uniform system to sacrifice all secondary views, and to incur all lesser hazards, to secure what he considered as the main object of the campaign. Serrurier, who commanded the blockading army, was hastily ordered to destroy as much as possible of the cannon and stores which had been collected with so much pains for the prosecution of the siege.171 A hundred guns were abandoned in the trenches, and Wurmser, on arriving at Mantua, found that Buonaparte had retired with a precipitation resembling that of fear.172
On the night of the 31st July this operation took place, and, leaving the division of Augereau at Borghetto, and that of Massena at Peschiera, to protect, while it was possible, the line of the Mincio, Buonaparte rushed, at the head of an army which his combinations had rendered superior, upon the right wing of the Austrians, which had already directed its march to Lonato, near the bottom of the lago di Guarda, in order to approach the Mincio, and resume its communication with Wurmser. But Buonaparte, placed by the celerity of his movements between the two hostile armies, defeated one division of the Austrian right at Salo, upon the lake, and another at Lonato. At the same time, Augereau and Massena, leaving just enough of men at their posts of Borghetto and Peschiera to maintain a respectable defence against Wurmser, made a forced march to Brescia, which they supposed to be still occupied by a third division of the Austrian right wing. But that body, finding itself insulated, and conceiving that the whole French army was debouching on them from different points, was already in full retreat towards the Tyrol, from which it had advanced with the expectation of turning Buonaparte's flank, and destroying his retreat upon Milan. Some French troops were left to accelerate their flight, and prevent their again making head, while Massena and Augereau, rapidly countermarching, returned to the banks of the Mincio to support their respective rear-guards, which they had left at Borghetto and Peschiera, on the line of that river.
They received intelligence, however, which induced them to halt upon this counter-march. Both rear-guards had been compelled to retire from the line of the Mincio, of which river the Austrians had forced the passage. The rear-guard of Massena, under General Pigeon, had fallen back in good order, so as to occupy Lonato; that of Augereau fled with precipitation and confusion, and failed to make a stand at Castiglione, which was occupied by Austrians, who intrenched themselves there. Valette, the officer who commanded this body, was deprived of his commission in presence of his troops for misbehaviour,173 an example which the gallantry of the French generals rendered extremely infrequent in their service.
Wurmser became now seriously anxious about the fate of his right wing, and determined to force a communication with Quasdonowich at all risks. But he could only attain the valley of the Chiese, and the right bank of the lago di Guarda, by breaking a passage through the divisions of Massena and Augereau. On the 3d of August, at break of day, two divisions of Austrians, who had crossed the Mincio in pursuit of Pigeon and Valette, now directed themselves, with the most determined resolution, on the French troops, in order to clear the way between the commander-in-chief and his right wing.
The late rear-guard of Massena, which, by his counter-march, had now become his advanced-guard, was defeated, and Lonato, the place which they occupied, was taken by the Austrians, with the French artillery, and the general officer who commanded them. But the Austrian general, thus far successful, fell into the great error of extending his line too much towards the right, in order, doubtless, if possible, to turn the French position on their left flank, thereby the sooner to open a communication with his own troops on the right bank of the lago di Guarda, to force which had been his principal object in the attack. But, in thus manœuvring,174 he weakened his centre, an error of which Massena instantly availed himself. He formed two strong columns under Augereau, with which he redeemed the victory, by breaking through and dividing the Austrian line, and retaking Lonato at the point of the bayonet. The manœuvre is indeed a simple one, and the same by which, ten years afterwards, Buonaparte gained the battle of Austerlitz; but it requires the utmost promptitude and presence of mind to seize the exact moment for executing such a daring measure to advantage. If it is but partially successful, and the enemy retains steadiness, it is very perilous; since the attacking column, instead of flanking the broken divisions of the opposite line, may be itself flanked by decided officers and determined troops, and thus experience the disaster