In the campaign of 1796, when the army of Moreau had been forced into a precipitate retreat by the admirable strategic operations of the Archduke Charles, the French forces owed their safety to the fortifications on the Rhine.  These works arrested the enemy’s pursuit and obliged him to resort to the tedious operations of sieges; and the reduction of the French advanced posts alone, Kehl and Huninguen, poorly as they were defended, employed all the resources of the Austrian army, and the skill of their engineers, from early in October till late in February.  Kehl was at first assaulted by a force four times as numerous as the garrison; if the enemy had succeeded, he would have cut off Moreau’s retreat, and destroyed his army.  Fortunately the place was strong enough to resist all assaults; and Moreau, basing himself on the fortresses of Alsace, his right covered by Huninguen, Neuf-Brisach, and Befort, and his left by the iron barrier of the Netherlands, effectually checked the waves of Austrian success.

Let us now turn to the campaigns of Napoleon.  In his first campaign in Italy, 1796, the general was directed “to seize the forts of Savona, compel the senate to furnish him with pecuniary supplies, and to surrender the keys of Gavi, a fortress perched on the rocky height commanding the pass of the Bocchetta.”  Setting out from Savona, he crossed the mountains at a weak point between the Alps and the Apennines, and succeeded in piercing the enemy’s line of defence.  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.”