MARENGO, a village of north Italy, on the road between Alessandria and Tortona, and E.S.E. of the gates of the former. It is situated on the Fontanone brook, a small affluent of the Tanaro which marks the western edge of the plain of Marengo, the scene of the great victory won by Napoleon Bona parte over the Austrians under Baron Melas (1729-1806) on June 14, 1800. The antecedents of the battle are described under FRENCH REVOLUTIONARY WARS.
The French army, uncertain of its opponent's position, had ad vanced westward from the Scrivia towards Alessandria on the I2th, and its outposts had reached the Bormida on the evening of the 13th. But contact with the main Austrian army was not ob tained, and on the assumption that it was moving towards either Valenza or Genoa Bonaparte weakened his army by considerable detachments sent out right and left to find the enemy and to delay his progress. Unknown, however, to Bonaparte Melas's army was still at Alessandria, and on the morning of June 14 it filed out of the fortress and began its advance into the great plain of Marengo, one of the few favourable cavalry battle-grounds in north Italy.
Gen. Victor had not carried out Bonaparte's evening order to destroy the bridges over the Bormida, and the dispersion of the French army allowed only a fragmentary, though most energetic, resistance to be offered to the Austrian onset. The latter, con siderably delayed at first by the crossing of the river Bormida, broke up into two columns,' advanced, the right by the main road on Marengo, the left on Castel Ceriolo. The former, per sonally commanded by Melas, was 20,000 strong, and Gen. Vic tor, its immediate opponent, about io,000, or including some 5,000 of Lannes' corps who fought on his right, about 15,000 strong; the Austrians were, moreover, greatly superior in guns (in all 192 to 14) and cavalry. The French disputed every yard of ground, holding their first line until they had by fire and counter attack forced practically the whole of the Austrian right to de ploy, and two hours passed before the Austrians managed to reach the Fontanone brook. But Victor's troops, being disorganized and short of ammunition, had then to retire more rapidly across the plain. The retreat was orderly, according to Victor's report, and made in echelon from the centre, and it is certain that at any rate the regiments held together, for the 6,000 Austrian sabres found no opportunity to charge home. Many guns and wagons were,
however, abandoned.
On the French right, opposed to the column of Lieut.-Field Marshal Ott, was Lannes, with some 4,00o men (excluding Watrin's division which was with Victor) against 7,50o. He too was after a time forced to retire, with heavy losses. Thus, about II A.M., Bonaparte, who was at some distance from the field, be came convinced that he had to deal with Melas's army. At once he sent out his staff officers to bring back his detachments, and pushed forward his only reserve, Monnier's division, to support Lannes and Victor. But before this help arrived Lannes had been driven out of Castel Ceriolo, and Victor and Watrin forced back almost to San Giuliano. A little after 2 P.M. Monnier's division (3,500) came into action, and its impetuous advance drove the Austrians out of Castel Ceriolo. But after an hour it was forced back in its turn, and by 3 P.M., therefore, the 20,000 French troops, disordered and exhausted, and in one line without reserves,' held a ragged line of battle to the right and left of San Giuliano. The best that could be expected was a prolongation of the struggle till nightfall and a fairly orderly retreat. Melas, slightly wounded and believing that the battle was won, returned to Alessandria, leaving a younger man, his chief of staff Zach, to organize the pursuit.
Then followed one of the most dramatic events in military his tory. Of the two detachments sent away by Napoleon in search of the enemy, one only received its orders of recall. This was Boudet's division of Desaix's corps, away to the south at Rivalta and at noon heading for Pozzolo-Formigaro on the Alessandria Genoa road. At I P.M. a brief message, "Revenez, au nom de Dieu!" altered the direction of the column, and between 4 and 5, after a forced march, the division, headed by Desaix, came on to the battle-field. It was deployed as a unit and moved forward at the word of command along the main road Alessandria-Tortona, the sight of their closed line giving fresh courage to the men of Lannes and Victor. Then, while on the other side Zach was array ing a deep column of troops to pursue along the main road, Napo leon and Desaix, themselves under fire, hastily framed a plan of 'A third column was sent out to the extreme right (3,00o under O'Reilly). This destroyed a small French detachment on the extreme left, but took little or no part in the main battle.