The siege of Mantua lasted from 4 June 1796 to 2 February 1797 with a short break where French forces under the overall command of Napoleon Bonaparte besieged and blockaded a large Austrian garrison at Mantua for many months until it surrendered. The siege was the focal point of the Italian Campaign of 1796-1797, lasting the vast majority of the campaign and being the hinge point that would determine which side would control Northern Italy. The eventual surrender, together with the heavy losses incurred during four unsuccessful relief attempts, led to Napoleon invading Austria and convincing the Austrians to sue for peace in 1797. The siege occurred during the War of the First Coalition, which is part of the French Revolutionary Wars. Mantua, a city in the Lombardy region of Italy, lies on the Mincio River.
After driving the Austrian army out of northwest and north-central Italy, the French invested the fortress of Mantua starting in early June 1796. In late July, a new Austrian commander, Dagobert Sigmund von Wurmser, led an army to the relief of Joseph Canto d'Irles's garrison from the north. Mantua was reached and the French were forced to abandon the siege. However, the Austrians were subsequently beaten in the battles of Lonato and Castiglione. Forced to retreat, Wurmser resupplied and reinforced the fortress with food and able-bodied troops. After withdrawing north up the Adige River, Wurmser planned to move his main army through the mountains to Bassano via the Brenta valley. From there he would mount the second relief of Mantua from the northeast. In an exceedingly bold maneuver, Bonaparte smashed Paul Davidovich's covering force and followed Wurmser down the Brenta valley. Overcoming the Austrian army at Bassano in early September, Bonaparte tried to destroy Wurmser but failed. Instead he chased the bulk of the Austrian army into Mantua. The garrison now counted 30,000 men, but cut off from outside help, disease and starvation began mowing down Wurmser's troops.
A new commander, József Alvinczi, led the third relief of Mantua in November. While Alvinczi marched from the northeast, Davidovich's column moved down from the north. Alvinczi defeated Bonaparte twice and moved to the gates of Verona while Davidovich drubbed his French opponent in the Adige valley. At his last gasp, Bonaparte crossed the Adige behind Alvinczi's left flank at Arcole. The fighting raged for three days but the French finally prevailed, forcing the Austrians to pull back. Free of Alvinczi, Bonaparte attacked Davidovich and forced his corps to retreat also. For the fourth relief of Mantua, Alvinczi advanced his main army from the north while sending two smaller columns to threaten the French from the northeast. The French crushed the Austrian main army at Rivoli. Leaving two divisions to finish off Alvinczi, Bonaparte rapidly moved south and arrived near Mantua in time to destroy one of the other Austrian columns. With no hope of further help, Wurmser surrendered Mantua in early February.
Background
Geography
After being defeated by General of Division Bonaparte's French army at the Battle of Borghetto, the Austrian army led by Feldzeugmeister Johann Beaulieu abandoned the line of the Mincio River, left a strong garrison in the fortress of Mantua, and retreated north to Trento. On 31 May, the French tried to rush the fortress but the attempt failed. The French invested the place on 3 June.Chandler Campaigns, p 89
Together with Legnago, Verona, and Peschiera, Mantua forms part of the famous Quadrilateral of fortresses. To this day, the city is bounded on its north and east sides by a large lake formed by the Mincio River. In 1796, Mantua was nearly surrounded by water and connected by causeways to the fortified suburbs of Cittadella to the north and San Giorgio to the east. In the 18th century, the city was notoriously unhealthy in the warm months. The nearby marshes and lakes were an ideal breeding ground for malaria-carrying mosquitoes, though no one understood this at the time.Boycott-Brown, p 362
Mantua lies in the Po River basin. The Po lies 13 km to the south of the city and Peschiera on Lake Garda is 32 km north. Running due east, a major road connected with Padua via Legnago. Another highway went northeast to Verona and Vicenza. Both roads linked with the Austrian frontier. A number of north-to-south running rivers provide defensible positions on the north side of the Po. The most important river is the Adige which rises in the Alps and runs south on the east side of Lake Garda, going past Verona and Legnago.
From Trento in the north, Austrian armies had secure communications with Innsbruck across the Brenner Pass. An Austrian army at Trento had three ways to reach the Po valley in 1796. The first route used the roads running parallel with the Adige on the east side of Lake Garda. The second route went west of Lake Garda via Riva and Lake Idro to either Brescia or Lonato del Garda. The third route lay to the east through Levico Terme and Borgo Valsugana, then south along the Brenta River valley to Bassano del Grappa. By holding both Trento and Bassano, an Austrian army could move troops and supplies through the mountains without the French being able to interfere.
Siege and blockade
First relief
The Castiglione 1796 campaign order of battle shows French and Austrian units and organizations during the first relief of Mantua.
By requisitioning cannon from all over northern Italy, Bonaparte assembled a siege train of 179 heavy guns. Siege parallels were opened on 4 June and General of Division Jean-Mathieu-Philibert Sérurier put in command of operations. Feldmarschall-Leutnant Canto d'Irles commanded the 14,000-man Austrian garrison. Meanwhile, the Austrians replaced Beaulieu with Feldmarschall Wurmser as army commander in Italy.
Wurmser launched the first relief of Mantua at the end of July as a three-pronged attack by 49,000 men. Feldmarschall-Leutnant Peter Vitus von Quosdanovich led a column of 18,000 soldiers to the west of Lake Garda. Wurmser commanded 24,000 men of the two center columns which moved down the Adige River east of Lake Garda. Feldmarschall-Leutnant Johann Mészáros von Szoboszló and 5,000 troops hovered to the east near Vicenza. Bonaparte, who had only 44,000 soldiers, posted his divisions in an arc to protect his siege of Mantua. General of Division André Masséna's 15,000 men held Rivoli Veronese on the upper Adige, General of Division Pierre Augereau with 5,000 troops held Legnago, Sérurier's 10,000 soldiers besieged Mantua, General of Division Pierre François Sauret's 4,500 men defended the west side of Lake Garda, General of Division Hyacinthe François Joseph Despinoy's 5,500 covered Peschiera, and 4,000 others were in reserve or on the march.Fiebeger, p 9-10
Wurmser pushed Masséna back and Quosdanovich quickly seized Brescia, forcing Bonaparte to lift the siege on 1 August. The siege cannon being too heavy to move quickly, the French burned the gun carriages and withdrew. The garrison retrieved the abandoned gun tubes and dragged them into the city. Up to this point, the French besiegers suffered 1,200 killed and wounded, plus 898 captured. The defenders lost 492 killed or died of disease, 395 wounded, and 87 captured or deserted.Smith, p 118 There were also 3,275 soldiers on the sick list.Boycott-Brown, p 387
After a complex series of actions, Quosdanovich's column came to grief at the Battle of Lonato on 3 August and retreated. Bonaparte then turned on Wurmser and defeated him at the Battle of Castiglione on 5 August. Before retreating up the Adige valley, Wurmser threw two brigades into the fortress and evacuated some of the sick. Because of the loss of his heavy cannons, Bonaparte could no longer try to reduce Mantua by breaching its walls. Instead, he was forced to blockade the city.
Second relief The Bassano 1796 campaign order of battle shows French and Austrian units and organizations during the second relief of Mantua.
At the beginning of September, 14,000 Austrians under Feldmarschall-Leutnant Paul Davidovich held the upper Adige valley to the north. With the rest of the army, Wurmser marched down the Brenta valley to the vicinity of Bassano. The Austrian plan was for both corps to probe cautiously forward. If an opportunity arose, they were to march to Mantua's relief. Wurmser's chief-of-staff, Feldmarschall-Leutnant Franz von Lauer believed that the French were incapable of quickly reacting to an Austrian offensive. This proved to be a serious miscalculation.Boycott-Brown, p 416 Bonaparte sent General of Division Claude-Henri Belgrand de Vaubois and 10,000 men north on the west side of Lake Garda. Masséna with 13,000 and Augereau with 10,000 men advanced north up the Adige valley. General of Division Charles Edward Jennings de Kilmaine blockaded Mantua with 8,000 in General of Division Jean Sahuguet's division and a 2,000-man reserve.Fiebeger, p 12
Bonaparte's concentration of three divisions overwhelmed Davidovich at the Battle of Rovereto on 4 September. Leaving Vaubois in Trento to watch the remnants of Davidovich's corps, Bonaparte boldly decided to cut loose from his supply line and follow in Wurmser's wake. He directed Masséna and Augereau east through Levico and Borgo, then south down the Brenta valley. Augereau dispersed the Austrian rearguard at Primolano on 7 September. The two French divisions fell upon Wurmser and beat him badly at the Battle of Bassano on 8 September. Instead of retreating to the east, Wurmser joined the division of Mészáros and headed west for Mantua with Bonaparte in hot pursuit. Hoping to annihilate his adversary before he reached Mantua, the French commander sent Augereau to Padua to prevent Wurmser from escaping to the east and Masséna through Vicenza and Arcole.
Masséna intercepted General-major Peter Karl Ott von Bátorkéz's vanguard at Cerea on 11 September, but the Austrian gamely held on until Wurmser's main force came up to deal the French a bloody repulse. Aided by a local guide, Wurmser slipped past Sahuguet's blocking force to reach the fortress the next day. The 1,600-man Austrian rearguard surrendered to Augereau at Legnago on 13 September.Boycott-Brown, p 433-434
Wurmser arrived at the fortress with 10,367 infantry and 2,856 cavalry, temporarily disrupting the siege on the eastern side of the city. On 15 September, the Austrian field marshal stood to fight a pitched battle on the east side of the Mincio, with his left flank at La Favorita Palace and his right in front of the San Giorgio suburb. Bonaparte sent Sahuguet to attack La Favorita and Augereau's division (temporarily led by General of Brigade Louis André Bon) to assault Wurmser's right. Masséna advanced in the center. Ott fought off Sahuguet all day, but the Austrian right and center crumbled. The Austrians withdrew into Cittadella and the French captured San Giorgio. Austrian losses numbered 2,452 menBoycott-Brown, p 435 and 11 guns, while the French lost 1,500 and nine guns.Smith, p 124
At this time, there were nearly 30,000 Austrians crowded into Mantua. Within six weeks, 4,000 died from wounds or sickness.Boycott-Brown, p 438 During the next two weeks Wurmser organized foraging expeditions to the south of the city which gathered some supplies for the beleaguered garrison. On 23 September, a sortie by Ott and General-major Ferdinand Minckwitz suffered a stinging defeat at Governolo with 1,000 casualties.Boycott-Brown, p 439 By 29 September, Kilmaine closely reinvested the fortress.
Third relief The Arcola 1796 Campaign Order of Battle shows French and Austrian units and organizations during the third relief of Mantua.