Thus it will be seen that the French were in possession of the whole of northern Italy lying between the Po and Switzerland. Looking south from Milan, Bonaparte had in his front the line of the Po, which he held from Chivasso to Cremona. Far away to his right was the Great St. Bernard Pass, which he had just crossed, and which was now guarded by the French garrisons of Fort Bard and Ivrea. To his left, at a distance of eighty miles, was the Mincio, which formed on that side the dividing line between the French and the Austrians; and in his rear were the St. Gothard and Simplon passes, which offered him a safe retreat into Switzerland in case he should meet with a reverse. Already, within this territory, he had seized all the Austrian communications, captured several Austrian garrisons, occupied several cities, and taken possession of immense quantities of provisions and munitions of war. Thus situated, Bonaparte was almost ready to strike the blow that should decide the fate of Italy. In a few days he would cross the Po, march through the Stradella Pass, and encounter Melas on the bloody field of Marengo. The delay at Milan was but the lull before the storm. While Bonaparte remained there, completing his arrangements and awaiting the arrival of Moncey, Melas was beginning to appreciate the situation, and, though still somewhat confused and undecided, was destined shortly to make an heroic effort to save his army. For several days after Melas reached Turin, he remained in doubt as to the intentions of Bonaparte. In fact, he was deceived by the preparations that Lannes had made to cross the Po at Chivasso. Again: in descending the river towards Pavia, Lannes so masked the main part of the Army of Reserve, that Melas did not immediately become aware of the movement on Milan. But on the 29th of May he learned that Bonaparte was marching on Milan; and, on the 31st, he learned that Moreau had defeated Kray, and that Moncey's corps was marching by way of the St. Gothard into Italy. At once he comprehended the vast plan of Bonaparte. He saw that nothing could now prevent the Army of Reserve from uniting with Moncey's corps; and that, with these combined forces, Bonaparte would doubtless march south from Milan, cross the Po, and sever the Austrian communications. Thus he saw himself being rapidly enclosed in a net from which there would soon be little or no hope of escape. Being now completely undeceived as to the intentions of Bonaparte, Melas had no further cause for delay. He must concentrate his troops at once, in order to break through the French forces rapidly closing in upon him. He must, if possible, preserve his communications, and thus save his army from capture or annihilation.