The king of Sardinia, jealous of Austrian influence, had refused to permit the Austrian army to garrison his line of fortifications.

Napoleon, profiting by his victorious attitude, the mutual jealousy of Austria and Sardinia, and the intrigues of his diplomatists, soon gained possession of these important works.

"_These Sardinian fortresses_," he wrote to the Directory, "_at once put the Republicans in possession of the keys of the Peninsula_." Basing himself on Coni, Mondovi, Ceva, Gavi, and Alessandria, with Tortosa as his depot of magazines, he advanced against Lombardy.

Now basing himself on the Adda and Po, with the fortress of Pizzighettone as the depot of his magazines, he advanced upon the line of the Adige.

Pechiera became his next depot, and he now had four fortresses in echelon between him and his first depot of magazines; and, after the fall of Mantua, basing himself on the Po, he advanced against the States of the Church, making Ferrara and then Ancona, his places of depot.
From the solid basis of the fortresses of Piedmont and Lombardy, "he was enabled to turn his undivided attention to the destruction of the Austrians, and thus commence, with some security, that great career of conquest which he already meditated in the imperial dominions." In this campaign of 1797, after scouring his base, he fortified Palma-Nuova, Osapo, &c., repaired the old fortifications of Klagenfurth, and, as he advanced, established, to use his own words, "a good _point d'appui_ at every five or six marches." Afterwards, when the Austrians had nearly wrested Italy from the weak grasp of Napoleon's successors, the French saved their army in the fortress of Genoa and behind the line of the Var, which had been fortified with care in 1794-5.