Battle of Marengo

Background

By the end of 1799 the War of the Second Coalition had gone badly for France. Austrian armies had retaken most of Italy, and Bonaparte, back from Egypt in October, seized power as First Consul in the coup of 18 Brumaire (9 November). The new regime had enemies in Paris and rivals in the army, and needed a victory.

In spring 1800 Vienna ordered General Michael von Melas, with over 100,000 men in Italy, about 82,000 of them mobile, to clear the peninsula and then invade France. In mid-April he advanced on Genoa, where Masséna was besieged. Meanwhile Bonaparte had gathered the Army of the Reserve, about 50,000 men, a mix of veterans and conscripts, in eastern France. Instead of marching to relieve Genoa directly, he crossed the Great St Bernard Pass between 14 and 20 May, came down into Lombardy behind Melas and entered Milan on 2 June. The French cut the Austrian supply route along the Po and took Pavia, Piacenza and Stradella.

Genoa surrendered on 4 June, freeing Austrian troops. On 9 June Lannes beat Ott at Montebello. Melas concentrated his army at Alessandria, behind the Bormida, and a double agent fed Bonaparte false reports of his intentions. Convinced that Melas would try to slip away rather than fight, Bonaparte spread his army out to catch him: Lapoype went north of the Po and Desaix marched south towards Novi with Boudet's division. On the morning of 14 June Melas came out of his bridgehead over the Bormida and attacked.

The armies

The French Army of the Reserve had about 22,000 men and only 15 guns on the field at dawn, rising to about 28,000–30,000 once Desaix arrived. Victor's corps (Gardanne's and Chambarlhac's divisions) held the front around Marengo; Lannes' corps, with Watrin's division, stood to its right; Murat commanded the cavalry, including Kellermann's heavy brigade. Bonaparte kept Monnier's division and the Consular Guard in reserve near his headquarters at Torre Garofoli. Desaix, with Boudet's division of about 6,000 men, was a march away to the south.

Melas brought about 30,000–31,000 men and some 100 guns. His army formed three columns: the main body under Melas and his chief of staff Zach, with Hadik's, Kaim's, Elsnitz's and Morzin's divisions, in the centre; O'Reilly's division of about 3,300 on the right; and Ott's wing of about 7,500 on the left, aimed at Castel Ceriolo. Nimptsch's 2,300 hussars and two batteries were sent off to meet a false report of Suchet's corps and took no part.

The armies differed in kind. Austria was stronger in cavalry and artillery, but its battalions fought in eighteenth-century linear order. French battalions, led by experienced officers and NCOs, could switch between line, column and mixed order as the ground demanded.

The battle

CDB90 records the battle as a single engagement, number 115 (MARENGO), from 09:00 to 21:00, with the Austrians as attacker. Times below are approximate and the sources differ by up to an hour.

The Austrian crossing (06:00–09:00). The Austrians began crossing the Bormida bridges around dawn. At about 07:00 Frimont's advance guard ran into Gardanne's division in front of Marengo, but the slow Austrian deployment gave Victor time to form behind the Fontanone, a marshy stream that was the only real obstacle on the plain. The main assault came at about 09:00. Bonaparte, at Torre Garofoli, at first took the cannonade for a diversion or a rearguard action.

The fight for the Fontanone (09:00–14:00). Hadik's division attacked Victor's line and was thrown back; Hadik was killed. Kaim's attack also failed. Lannes came up on Victor's right at about 10:00 and extended the line north. At about 11:00 Bonaparte realised that this was Melas's whole army, recalled Desaix and moved his reserve forward; Kellermann's heavy cavalry scattered Austrian horse threatening Victor's left. But O'Reilly turned that flank, and Ott took Castel Ceriolo around 11:30–12:00 and began working round the French right. The Austrians bridged the Fontanone, French cartridges ran short, and in the early afternoon Marengo village fell. By about 14:00 Victor and Lannes could hold no longer.

The French retreat (14:00–17:00). Bonaparte committed Monnier's division and the Consular Guard near Castel Ceriolo to cover the right, but Austrian cavalry under Frimont broke the Guard. The French fell back east across the plain towards San Giuliano. Melas, slightly wounded and believing the day won, rode back to Alessandria and handed command to Zach and Kaim. The Fondation Napoléon puts his departure at about 14:00; Wikipedia places it after the Guard's destruction, nearer 16:00. The Austrian pursuit, led by Zach's column, was slow.

Desaix and Kellermann (17:00–19:00). Desaix reached San Giuliano with Boudet's division, about 5,000–6,000 men, at around 17:00. Bonaparte halted the retreat and turned the army round. Marmont massed a battery of about 18 guns, his own and Desaix's, and fired canister into the head of Zach's column. Desaix then attacked at the head of the 9th Light Demi-Brigade and was shot dead almost at once, but his men pushed the leading Austrians back. As Boudet's attack lost momentum, Kellermann, with about 400 heavy cavalry, charged the flank of Lattermann's grenadiers. The column broke. Zach and at least 2,000 men were captured.

The Austrian collapse (19:00–21:00). The defeat of the column spread panic through the Austrian centre, which streamed back to the Bormida bridges. O'Reilly and Frimont held Marengo village long enough for it to reach safety behind the river. By nightfall the French held the field; by about 22:00 they had reoccupied their morning positions.

Aftermath

Austrian losses were about 6,000–6,500 killed and wounded and some 8,000 captured, with about 40 guns; a modern count gives 9,402 in all. French losses were about 5,600–7,000, roughly a quarter of the army, among them Desaix. On 15 June Melas signed the Convention of Alessandria: the Austrians withdrew behind the Mincio and handed over Genoa, Alessandria, Turin, Milan and the other fortresses of Piedmont and Lombardy. The war in Italy was effectively over, though peace came only after Moreau's victory at Hohenlinden in December.

Politically the battle mattered more than militarily. It saved the young Consulate and secured Bonaparte's position in Paris.

It also became one of his most worked-over legends. The army bulletin of 15 June conveyed the fighting but not the desperation, and credited Bessières's charge rather than Kellermann's. Three increasingly glamorised official reports followed during his reign; Berthier's Relation presented the retreat as a planned manoeuvre and Desaix's division as a reserve held back on purpose, which was false. Desaix's death was made into a heroic cult, and the Marengo march replaced the Marseillaise as the anthem of the Empire. David Chandler, among others, gives the day to Desaix, Marmont and Kellermann rather than to Bonaparte.

Wargaming it

Marengo is a manageable, open battle with a famous reversal built in. Two armies of about 30,000 fight on a plain some ten miles across between the Bormida and the Scrivia, so it suits brigade or regiment level, with battalion or regimental bases and turns of 20–30 minutes, on a single table. A large skirmish-to-grand-tactical game can also take just Desaix's counter-attack.

The terrain is simple but matters: the marshy Fontanone and Marengo village for the morning, Castel Ceriolo on the open northern flank, and the open ground towards San Giuliano across which the French retreat and Zach pursues. The Austrian bridgehead constrains how fast Melas can deploy.

Timing is the game. The Austrians must break Victor and Lannes before Desaix arrives at about 17:00; a scenario should bring him on by a variable timetable. Austrian players have more cavalry and guns but more rigid infantry; the French have flexible infantry and very few guns until Marmont's battery forms.

The what-ifs are strong. What if Melas stays on the field and drives the pursuit himself? What if Nimptsch's 2,300 hussars are not sent away, or Lapoype's 3,500 men are recalled too? What if Desaix is a few hours later, or Kellermann charges too early? A campaign game can begin with Bonaparte's dispersal and the false intelligence of the double agent.

Maps and pictures

Paintings and prints

Paintings and prints of the battle, from the time and the century after, by year: free-to-use pictures from the battle's category on Wikimedia Commons. Each opens its file page there, with the full caption and source.