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BATTLE // January 1, 1800

Second Italian Campaign

Overview

The Marengo campaign saw a Habsburg Austrian army led by General der Kavallerie Michael von Melas fight against the defending French Army of Italy under General of Division (GD) André Massena and the invading French Reserve Army commanded by First Consul Napoleon Bonaparte. In early April, Melas launched a successful offensive that split the outnumbered Army of Italy and initiated the Siege of Genoa with Massena's forces trapped within the city. In mid-May, Bonaparte led the Reserve Army across the Great St Bernard Pass and into the Aosta Valley. After encountering a serious delay at Fort Bard, Bonaparte's forces broke into the plains of the Po Valley toward the end of May. At Turin, Melas blocked the direct route to Genoa, but Bonaparte's forces instead seized Milan and began severing the supply lines between Melas' army and Austria. After a long siege, Massena finally surrendered Genoa in early June, but by that time Melas' forces were isolated in northwest Italy. Melas tried to break out of the trap in the Battle of Marengo on 14 June 1800 and nearly succeeded because Bonaparte spread his army too thin. However, late-arriving troops defeated the Austrians and Bonaparte compelled Melas to evacuate northwest Italy as the price of a negotiated truce.

Overview adapted from Wikipedia, licensed under CC BY-SA 4.0.

Significance

The Second Italian Campaign (the Marengo campaign) decided control of northwest Italy and forced the Habsburg army out of the region through a combination of strategic encirclement and a climactic pitched battle. After Austrian General von Melas split the French Army of Italy and besieged Massena's forces in Genoa, Bonaparte answered by crossing the Great St Bernard Pass with the Reserve Army and seizing Milan, cutting Habsburg supply lines between Melas and Austria rather than driving directly to relieve Genoa. Genoa fell, but Melas now found his army isolated in northwest Italy. His attempted breakout at the Battle of Marengo on 14 June 1800 nearly succeeded, exploiting Bonaparte's overextended dispositions, but late-arriving French forces reversed the engagement. The result was a negotiated truce under which Melas evacuated northwest Italy entirely, restoring French dominance over the region and substantially weakening Habsburg strategic position in the War of the Second Coalition.

Tactics

Bonaparte crossed the Great St Bernard Pass in mid-May and descended into the Aosta Valley, where a serious delay at Fort Bard slowed his advance before his forces broke into the Po Valley plains. Rather than taking the direct route to Genoa blocked by Melas at Turin, Bonaparte seized Milan and moved to sever Habsburg supply lines between the Austrian army and Austria itself. This maneuver isolated Melas in northwest Italy. At the Battle of Marengo, Bonaparte spread his army too thin, allowing Melas to nearly break out of the ; late-arriving French troops ultimately defeated the Austrians and secured the campaign's outcome.

Forces & casualties

Troop strength

  • France28,000
    medium
  • Habsburg monarchy30,000
    medium

Both sides were near-evenly matched in numbers

Casualties

  • France10,600–19,900
    medium54% loss rate
  • Habsburg monarchy21,427–26,616
    medium80% loss rate

Commanders (16)

France

Habsburg monarchy

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Last verified June 2026
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