Napoleon has himself observed, that no country in the world is more distinctly marked out by its natural boundaries than Italy.[84] The Alps seem a barrier erected by Nature herself, on which she has inscribed in gigantic characters, "Here let ambition be staid." Yet this tremendous circumvallation of mountains, as it could not prevent the ancient Romans from breaking out to desolate the world, so it has been in like manner found, ever since the days of Hannibal, unequal to protect Italy herself from invasion. The French nation, in the times of which we treat, spoke indeed of the Alps as a natural boundary, so far as to authorise them to claim all which lay on the western side of these mountains, as naturally pertaining to their dominions; but they never deigned to respect them as such, when the question respected their invading, on their own part, the territories of other states, which lay on or beyond the formidable frontier. They assumed the law of natural limits as an unchallengeable rule when it made in favour of France, but never allowed it to be quoted against her interest. [Sidenote: COMMANDER-IN-CHIEF.] During the Revolutionary War, the general fortune of battle had varied from time to time in the neighbourhood of these mighty boundaries. The King of Sardinia[85] possessed almost all the fortresses which command the passes on these mountains, and had therefore been said to wear the keys of the Alps at his girdle. He had indeed lost his Dukedom of Savoy, and the County of Nice, in the late campaigns; but he still maintained a very considerable army, and was supported by his powerful ally the Emperor of Austria, always vigilant regarding that rich and beautiful portion of his dominions which lies in the north of Italy. The frontiers of Piedmont were therefore covered by a strong Austro-Sardinian army, opposed to the French, of which Napoleon had been just named commander-in-chief. A strong Neapolitan force[86] was also to be added, so that in general numbers their opponents were much superior to the French; but a great part of this force was cooped up in garrisons which could not be abandoned.