Marexgo, a village of Piedmont, Italy, on; the river Bormida, 2 m. S. E. of Alessandria, I situated on an extensive plain of the same name, where a victory was gained by Bonaparte over the Austrian general Melas, June 14, 1800. Bonaparte, having crossed the Great St. Bernard in the latter part of May and overrun a large portion of Lombardy, entered tin-plain of Marengo with the object of preventing Melas, who had concentrated his forces at Alessandria, from escaping him by a march southward to Genoa. On the morning of June 14 the village of Marengo was occupied by two French divisions under Victor. Melas attacked them with 31.000 men and 200 cannon, and at 11 o'clock, when Bonaparte arrived, Victor's divisions with Lannes's corps were in full retreat. The fugitives, reanimated by the presence of Bonaparte, rallied and kept the Austrians in check. At 4 P.M. Desaix'a corps, which was on the road to Novi, and had been hurriedly recalled, arrived on the field and took position on the left, while Victor and Lannes reformed on the right, with Marmont's masked battery in the rear. Thus reinforced, Bonaparte turned the tide and completely overwhelmed the Austrians, the younger Keller-mann's cavalry charge deciding the day.

The Austrians lost 7,000 killed and wounded, 3,000 prisoners, 20 pieces of artillery, and 8 standards. The French, who brought about 28,000 men into the field, lost about 7,000 in killed (including Desaix) and wounded and 1,000 prisoners. An armistice followed, by the terms of which the Austrians were allowed to retire beyond the Mincio on condition of giving up all their fortified places in Italy wot of that river.