The Campaign of Marengo, With Comments

by Herbert H. Sargent

The problem before Masséna was to hold in check the Austrians in Italy until Bonaparte could perfect his arrangements, cross the Alps, and strike the Austrian rear. Masséna could not expect to do more than this; for he could not take the offensive single-handed against an Austrian army three times the size of his own. Moreover, he was in possession of the strong defensive positions of Genoa, of the Apennines and Maritime Alps, and of the line of the Var, where inferior numbers could make a vigorous resistance against greatly superior forces. Masséna could not know how soon Bonaparte would cross the Alps. His object, therefore, was so to arrange his troops as to enable them to hold out as long as possible.

At the outset of the campaign the Army of Italy was stationed as follows: eight thousand were at Genoa; twelve thousand, in the vicinity of Savona; twelve thousand, at the Tenda Pass, at Nice, and along the Var; and four thousand, in the Mont Cenis Pass. By examining the several positions on the map, it will be seen that the French forces were greatly scattered. Thirty-two thousand, under the direct command of Masséna, were defending the line of the Apennines and Maritime Alps from Genoa to the Col di Tenda, a distance of about seventy-five miles; and four thousand, under Thurreau, were holding the Mont Cenis Pass, which lies in the French Alps about one hundred and twenty miles north of Nice.

Inasmuch as the direct road from Italy into France crossed the Alps over this pass, it was necessary to leave Thurreau's detachment there. Otherwise an Austrian corps of several thousand could have crossed the Alps at this point, thence have marched south along the west side of the mountains, and have attacked the French on the Var in rear, while Melas with his main forces was advancing across the Apennines to attack them in front. Moreover, in this favorable position, Thurreau, unless strongly opposed, could descend the Alps and fall upon the flank and rear of the Austrians as they advanced towards Nice. It was necessary, therefore, for Melas to leave ten or twelve thousand soldiers of the Austrian rear guard near the Italian entrance to the Mont Cenis Pass in order to hold Thurreau in check. Thus, though this French detachment could take no active part in the engagements along the Apennines and Maritime Alps, its four thousand men did good service in the struggle by rendering nugatory the fighting power of a much larger Austrian force.

Since the French along the Apennines and Maritime Alps occupied a front of about seventy-five miles in extent, they could not concentrate rapidly. Consequently, Melas could throw a strong force against some point of their long line with great hope of success. In fact, by attacking the centre of their line with superior numbers, he could cut the Army of Italy in two. Having in this way separated Masséna from Suchet, Melas could concentrate an overwhelming force against each in succession, and thus defeat them separately. Moreover, this movement would cut the communications of Masséna with France, and compel him to seek safety in Genoa, where the opposition of superior numbers and the scarcity of provisions must eventually force him to surrender.

Strategically, therefore, the situation of the Army of Italy was faulty; yet it must be remembered that the lack of provisions was the principal cause that led Masséna to adopt this plan. In order better to subsist his troops, he had scattered them. But was there no other course that offered him greater advantages? A discussion of the subject should throw light on this question.

First: He might have left detachments to hold the Cadibona and Ormea passes, and have concentrated the bulk of his army in rear of the Tenda Pass in the vicinity of Nice. Had he adopted this course, his troops would have been united, and could have drawn their provisions direct from France. But no other advantages would have resulted. With the French in this position, Melas could have attacked the passes of the Apennines in force, and have gained possession of the Genoa-Nice road; which operation would have compelled Masséna to fall back on the Var. There he might have been able to make a successful stand for a time. But should the Austrians once force this position, there would be no further obstacle to the invasion of France. To adopt this plan would undoubtedly have been a mistake; for it involved the abandonment of Genoa, which was so strong, both naturally and artificially, that a small force could hold it for a long time against superior numbers. Moreover, in a defensive campaign, when the odds are greatly in favor of the attacking army, and when the object is to gain time, advantage should be taken of every strong position.

Second: Masséna might have left small detachments to hold the passes of the Apennines and Maritime Alps, and have concentrated the rest of his army at Genoa. Indeed this was the plan that Bonaparte had ordered Masséna to carry out; but it presented great difficulties. Provisions were scarce at Genoa. Had Masséna increased his strength there to thirty thousand soldiers, starvation and disease would sooner have done their deadly work. Moreover, the greater fighting power thus obtained would have availed him nothing; for with half the number he in fact held the city till the food was exhausted. Had Masséna adopted this course, undoubtedly he must have surrendered at least three weeks earlier. In that case, the Austrians would have crossed the Var into France, and Bonaparte would have abandoned his march into Italy. In that case, the decisive struggle between Melas and Bonaparte would doubtless have taken place in the valley of the Rhone instead of in the valley of the Po. Indeed, it is not improbable to assume that, had Masséna attempted to carry out either one of the plans mentioned, Bonaparte would have been obliged to change the entire conduct of the campaign. In war small matters often determine great events.

Under the circumstances then existing, Masséna was justified in not carrying out Bonaparte's instructions; nevertheless, had he fully appreciated the advantages of the plan, he would undoubtedly have made a greater effort to collect supplies at Genoa. Inasmuch as he took command of the Army of Italy before the arrival of the British fleet in the Gulf of Genoa, possibly he might have shipped sufficient grain from Toulon to supply the Army of Italy during a siege of several months. For the purpose of this discussion, let us assume that he had done so; and that, in accordance with Bonaparte's orders, he had left a few thousand men to hold the passes of the Apennines and Maritime Alps, and had collected about thirty thousand at Genoa. What would have been the result? What are the advantages of this situation? Surely, they are many; for Bonaparte himself originated the plan.

Since the mountains and outlying works surrounding Genoa made it a veritable stronghold, Bonaparte calculated that the Army of Italy could maintain itself there against greatly outnumbering forces; and that the Austrians would hardly dare to force the Apennines and push forward in order to invade France while thirty thousand men remained undefeated in their rear. In this position, too, Masséna could, at any time, leave a small force to hold Genoa, then march rapidly westward along the south side of the Apennines, and arrive before any one of the threatened passes with almost his entire army; or should the Austrians force the Apennines and advance towards France, he could fall upon their flank and rear, and perhaps sever their communications, while his own communications with Genoa would be protected by the mountains on one side and by the sea on the other. In fact, this position would enable him to take advantage of the topography of the country to the fullest extent. If he should make an attack in force upon the Austrians from one of the passes in his possession, the mountains would protect him during his concentration, and would give strength to his position after his forces had united. If he should remain at Genoa, the fortifications and natural obstacles there would increase enormously his fighting power. It is evident, too, that he might march out of the city, force his way through the Apennines, and cut the communications of the Austrians in the valley of the Po. If, while holding the Apennines, he should advance with his main army over the Genoa-Nice road to attack the Austrians, he would be in a position where a victory would bring him great results, and where a defeat would do him but little harm. Should he be successful, he could sever the Austrian communications and perhaps ruin their army; should he be repulsed, he could fall back and seek safety in Genoa. "If," says Bonaparte in his instructions to Masséna, "Melas appear in the direction of Nice, you being at Genoa, let him come on, stir not from your position: he will not advance far if you remain in Liguria, ready to throw yourself upon his rear, or upon the troops left in Piedmont."