Campaigns of 1800 in the French Revolutionary Wars

The French Revolutionary Wars continued from 1799 with the French fighting the forces of the Second Coalition. Napoleon Bonaparte had returned from Egypt and taken control of the French government. He prepared a new campaign, sending Moreau to the Rhine frontier and personally going to take command in the Alps, where French forces had been driven almost out of Italy in 1799.

At the start of the campaigning season of 1800, the Austrians had strong armies North and South of the Alps


 * about 120,000 men in the Black Forest under Pál Kray (defending the direct (Rhine – Danube) route from France to Vienna
 * about 100,000 men in Northern Italy under Michael von Melas defending the Austrian possessions in Northern Italy, and the Po valley, which Napoleon had used as a backdoor to Vienna in his previous Italian campaigns

The French had

Both the Austrians and the French decided to make their main effort in Italy. (Bonaparte would have preferred the main attack to be on Kray by a flanking move through Northern Switzerland, but the working relationship with Moreau was poor).
 * about 120,000 men under Moreau facing Kray
 * about 40,000 men under André Masséna holding Genoa and preventing invasion of Southern France from Italy
 * about 50,000 men under Berthier forming the Army of the Reserve and centred on Dijon

Italy
Melas attacked first, and by the third week in April had advanced to the Var, with Massena and half his army in Genoa besieged by land by the Austrians and under tight blockade by the Royal Navy. In response Berthier moved – not to the threatened frontier, but to Geneva- and Massena was instructed to hold Genoa until 4 June.

The Army of the Reserve was joined by Napoleon, and in mid-May set out to cross the Alps to attack the Austrian rear. The bulk of the army crossed by the Great St. Bernard Pass, still under snow, and by 24 May 40,000 troops were in the valley of the Po. Artillery was manhandled over with great effort and ingenuity; however an Austrian-held fort on the Italian side (although bypassed by infantry and cavalry) prevented most of the artillery reaching the plains of Northern Italy until the start of June.

Once over the Alps, Napoleon did not proceed directly to the relief of Genoa. Instead, he advanced on Milan, to improve his lines of communication (via the Simplon and St Gotthard passes) and to threaten Melas's lines of communication with Mantua and Vienna, in the belief that this would cause Melas to raise the siege of Genoa. He entered Milan on 2 June and by crossing to the South bank of the Po completely cut Melas's communications. Taking up a strong defensive position at Stradella, he confidently awaited an attempt by the Austrian Army to fight its way out.

However, Melas had not raised the siege of Genoa, and on 4 June, Massena had duly capitulated. Napoleon then faced the possibility that, thanks to the British command of the Mediterranean, far from falling back, the Austrians could instead take Genoa as their new base and be supplied by sea. His defensive posture would not prevent this; he had to find and attack the Austrians before they could regroup. He therefore advanced from Stradella towards Alessandria, where Melas was, apparently doing nothing. Convinced that Melas was about to retreat, Napoleon sent strong detachments to block Melas's routes northwards to the Po, and southwards to Genoa. At this point, Melas attacked, and for all the brilliance of the previous campaign, Napoleon found himself at a significant disadvantage in the consequent Battle of Marengo (14 June). Napoleon was effectively defeated in a tough battle in the morning and early afternoon; Melas, thinking he had already won, had turned over delivery of the coup de grace to a subordinate, when the prompt return of a detached French force under Desaix and a vigorous French counter-attack (in the course of which Desaix was killed) converted the battle into an important French victory.

Melas promptly entered into negotiations which led to the Austrians evacuating Northern Italy west of the Ticino, and suspending military operations in Italy.

Napoleon returned to Paris after the victory, leaving Brune to consolidate in Italy and begin a march toward Austria.

Germany
In May and June, Moreau invaded across the Southern part of the Rhine with 100,000 men, converging on Bavaria. Gen. Kray's Austrians were completely outflanked and beaten at Stockach, Engen, Messkirch and Biberach, being forced to take refuge in Ulm. A long armistice followed, after which Kray was replaced by the Archduke John, with the Austrian army retiring behind the river Inn. When the armistice ended, John advanced over the Inn towards Munich and Moreau defeated the Austrians overwhelmingly in the forests before the city at Battle of Hohenlinden on 3 December. Moreau began a march on Vienna, and the Austrians soon sued for peace, ending the war on the continent.

Egypt
Meanwhile, Kléber remained trapped in Egypt by the British fleet. He negotiated the Convention of El-Arish with Britain and Turkey to allow him to evacuate by sea, but Britain later repudiated the agreement. Kléber won a battle against the Turks at Heliopolis in March, but was assassinated later in June.