Battle of Piacenza

The Battle of Piacenza^[3] or Battle of St. Lazaro^[4] (16 June 1746) was fought between a Austrian army and a Bourbon army near Piacenza, in Northern Italy during the War of the Austrian Succession. The Bourbon army consisted of a large Spanish force commanded by Jean Bonaventure du Mont, comte de Gages and a somewhat smaller French corps led by Jean-Baptiste Francois des Marets, marquis de Maillebois. Gages' command included allied Neapolitan and Genoese soldiers. The Austrian army was commanded by Josef Wenzel, Prince of Liechtenstein. The Bourbon generals determined to attack because the Austrians were about to be reinforced by a Sardinian corps. The Franco-Spanish assault was anticipated by the Austrian generals and it failed with heavy losses. The defeat caused the Bourbon army to retreat to Genoa, though it had to fight its way out at the subsequent Battle of Rottofreddo.

Prince Franz Josef I and Louis-Joseph de Montcalm were among the notable combatants.

On 16 December 1740, the Kingdom of Prussia invaded and overran Silesia, a province of Habsburg Austria. This event started the War of the Austrian Succession.^[5] Aggressive diplomacy by the Kingdom of France lured the Electorate of Bavaria and the Electorate of Saxony into the anti-Austrian alliance. On 15 September 1741, a Franco-Bavarian army captured Linz.^[6] Prague was captured by a Franco-Bavarian-Saxon army on 25 November 1741.^[7] With most of Austria's army committed to the war north of the Alps, King Philip V of Spain and his Queen Elizabeth Farnese aimed to grab Habsburg territory in Italy for their son Don Philip. Avoiding an understrength British naval squadron, Spain landed 14,000 troops in Italy in November 1741 and 12,800 more in January 1742. This menacing move drove a wavering Kingdom of Sardinia into alliance with Austria.^[8] After ten months of inconclusive campaigning, 13,000 Spanish under Jean Thierry du Mont, comte de Gages fought 11,000 Austro-Sardinians under Field Marshal (FM) Otto Ferdinand von Abensperg und Traun on 8 February 1743. In the Battle of Campo Santo, the Allies compelled Spain's army to abandon Bologna and fall back to Rimini.^[9]

An Austrian attempt led by Johann Georg Christian, Prince of Lobkowicz to conquer Naples was repelled at the Second Battle of Velletri on 10–11 August 1744.^[10] That year, a 33,000-man Franco-Spanish army invaded Piedmont from the southwest.^[11] The Bourbon allies defeated Sardinian King Charles Emmanuel III at the Battle of Madonna dell'Olmo on 30 September 1744. Nevertheless, the attempted siege of Cuneo failed when Sardinian resistance and the weather compelled the Franco-Spanish army to retreat.^[12] The Bourbon allies' 1745 attempt to penetrate Piedmont from the southwest proved more successful. The Spanish army under Gages captured Novi in June and Tortona in August. The French under Jean-Baptiste Francois des Marets, marquis de Maillebois seized Acqui in July. A Spanish corps also seized Piacenza, Parma, and Pavia. With 50,000 troops, the Franco-Spanish allies defeated Charles Emmanuel's 30,000 men at the Battle of Bassignano on 27 September 1745.^[13]

After Bassignano, the French government decided to reduce its Italian commitment. On the other hand, Elizabeth Farnese demanded that her Spanish generals capture Milan. She got her way on 28 November 1745 when Gages led the Spanish army across the Po River. Outnumbered, the Austrian commander Josef Wenzel, Prince of Liechtenstein abandoned Milan. The city was occupied by the Spanish on 16 December and Don Philip promptly declared himself king. By the end of 1745, Austrian troops were absent from Lombardy except for garrisons in Mantua and the Milan citadel. Maillebois foresaw that his ally was overextended, but Don Philip and the Spanish government were not listening.^[14]

The Treaty of Dresden, signed on 25 December 1745, ended the conflict between Prussia, Austria, and Saxony^[15] known as the Second Silesian War.^[16] This led King Charles Emmanuel and his advisors to hope that Austria would soon transfer troops to Italy. In order to buy time for this to happen, the Kingdom of Sardinia signaled that it was ready to open talks with the French.^[15] In fact, the Habsburg Queen Maria Theresa immediately ordered Maximilian Ulysses Browne and 10,000 Austrians to march from Heidelberg to Italy.^[17] The French diplomat René Louis de Voyer de Paulmy, Marquis of Argenson began to negotiate with Charles Emmanuel in the hope of detaching Piedmont from its alliance with Austria. The two parties agreed that the truce would expire at the end of February 1746, if no agreement was reached. The gullible Argenson even insisted that Maillebois suspend the siege of Alessandria on 17 February in order to show France's good faith. The Spanish monarchs did not trust the Sardinian king and tried unsuccessfully to bribe Argenson to stop the talks.^[18]

On 1 March 1746, the deadline expired and Charles Emmanuel secretly resumed the war; his troops began to move towards the French positions. On 5 March 1746, the Sardinian army^[15] under Karl Sigmund Friedrich Wilhelm Leutrum von Ertingen^[19] launched an attack on Asti, taking its French garrison by surprise. Three days later, the 5,000-man garrison surrendered after Asti's walls were breached in two places.^[15] Fearful of being cut off from Genoa and France, Maillebois evacuated the Tanaro valley and withdrew to Novi. The Sardinians soon recaptured Casale and Valenza.^[19] The Spanish authorities were furious with Argenson, who at least admitted his blunder. Austrian numbers in Italy were bolstered by 30,000 soldiers transferred from Germany across the Alps to Italy.^[18] This reinforcement raised the Austro-Sardinian army to a total of 76,000 troops.^[19]

The surrender of Asti caused French morale to plummet and within a month the army of Maillebois lost 15,000 men to desertion, illness or capture. Gages' Spanish army sat still at Piacenza, uncertain of what course of action to take in the face of the new danger caused by the Austrian concentration. Under orders from the Spanish monarchs to hold Milan, Don Philip also sat immobilized. The 45,000-strong Austrian army advanced adroitly to enfold its opponents.^[20] Its commander, Prince Liechtenstein was accompanied by the veteran generals Browne, Franz Leopold von Nádasdy, and Johann Leopold Bärnklau.^[21] Don Philip abandoned Milan and escaped to Pavia. On 20 March 1746,^[20] Bärnklau's troops retook Milan and laid a heavy hand on the territory of Cremona. Another Austrian column seized Guastalla and the Marquis of Castellar's Spanish soldiers were forced to abandon Parma.^[4] Reggio was also taken by the Austrians by the end of April. The Austrians concentrated at Parma while the various components of Gages' army gathered at Piacenza.^[20]

Gages and Don Philip were under categorical orders from the Spanish monarchs to hold onto Piacenza. To demonstrate Bourbon cooperation, King Louis XV instructed Maillebois to follow Don Philip's orders regardless of his line of communication. The Austrians were surprised that their Bourbon foes clung to Piacenza rather than retreating to Genoa. In May 1746, though Liechtenstein suffered from poor health, his army took a position south of Piacenza and began fortifying it. Since the fortifications of Piacenza were in poor condition, Gages encamped his army on the glacis and constructed his own field works. Gages' 25,000 troops included Genoese and Neapolitan contingents that suffered particularly from disease. Desertions and sickness among his Spanish troops also took their toll. Earlier, Gages asked assistance from Maillebois, but the French commander put off his request by only sending ten battalions while keeping the bulk of his forces at Novi. Only after receiving direct orders from Louis V, did Maillebois finally concentrate 15,000 French troops near Piacenza, with the last soldiers arriving on 14–15 June.^[22]

According to historian Reed Browning, the Austrians enjoyed a manpower advantage of 45,000 men against 40,000 Bourbons and allied troops. A Sardinian force numbering 10,000 men followed Maillebois and was expected to reinforce the Austrian army. Since this would give Liechtenstein a 15,000-man advantage, Maillebois convinced Gages to order an immediate attack. Gages, who had time to observe his enemy's positions, planned to hold the Austrian center in place with an artillery bombardment while assaulting both of his opponent's flanks. The Bourbon right flank was ordered to outflank the Austrian left flank while sending a column on a wider sweep to hit its rear. Meanwhile, the Bourbon left was directed to strike the Austrian right flank in order to bend it back toward the center. Unfortunately for the French, the Austrian left flank commander Browne guessed what his opponents intended and shifted his units to block it. Antoniotto Botta Adorno commanded the Austrian right and simply put his troops on the alert.^[23] Statistician Gaston Bodart credited the Austrians with 40,000 soldiers while stating that the Franco-Spanish army numbered 44,000.^[3]

Since the Austrian army outnumbered De Gages' army by some 15,000 men, he worked out a plan which would make an Austrian assault costly and invite a Spanish counterstroke. He hoped this plan would win him the battle. Rejecting a stand in the crumbling town of Piacenza, Gages ordered ditches and artillery emplacements to be dug which would become a defensive line that the Austrians would have to attack. De Gages also ordered his troops to scout the areas to the north of Piacenza. Maillebois' arrival gave the Spanish general a combined strength of 40,000. However, this began to put a severe strain on the food supplies in the area. Additionally, a Piedmontese army of 10,000 men was approaching from the west which would firmly tip the balance in numbers in favor of the Austrians.

With the Piedmontese only a day's march away, the French marshal urged that an immediate attack should be launched against the Austrians. Instead of the original plan, the Spanish commander would now hold his center lightly while concentrating on the flanks. The attack on the Austrian's left would entail pushing it back towards the Austrian center. In an unorthodox move, De Gages asked Maillebois to take his troops beyond the extreme right of the line, encircle the Austrian right flank and fall on its rear. The battle was set to begin at sunrise on the 16th.

The Austrians had spent the last few months placing their artillery, seizing Bourbon outposts, and gathering food supplies. In the Austrian camp, the mood was one of confident victory. The Austrian plan was much more simple than the Bourbon one. They would let Gages waste his troops against their position. Once the attack had run out of steam, they would counter-attack. On the morning of the 15th, they began to deploy their forces to the north of Piacenza.

On the morning of June 16, the Austrian artillery opened fire on the Bourbon camp opposite them. At the same time, the Franco-Spanish army began its assault upon the Austrian lines. Marshal Maillebois' plan began to fail a few minutes after the start of his assault. Instead of a clear descent upon the Austrian rear, the marshal was unnerved to see Browne's troops drawn up in front of him behind a canal. Furthermore, the French force had emerged in the wrong place. The narrow valley they had gone into provided a bottleneck, and as soon as they emerged they were attacked by the Austrians. The marshal tried to bring more troops into action, but his men could not get near the Austrians due to the intensity of their fire. Finally, Browne advanced his troop over the canal and the assault collapsed, many Frenchmen being cut to pieces in the narrow gully.

On the other flank, Gages had been able to advance his men right up to the Austrian lines. His troops were slowly pushing the Austrians back in what seemed to be a much more even battle. However, Johann Leopold Bärnklau finally managed to draw the Austrian cavalry into the fight causing the Spanish line to break under the pressure. With the Spanish retreating towards Piacenza, the Austrians were able to give chase. By two pm, the battle was over and so were Bourbon hopes in Italy.

According to Browning, the Austrian army sustained 3,400 casualties including 700 dead. The Spanish army suffered 9,000 casualties while the French lost 4,000, for a total of 13,000 casualties. The Franco-Spanish army about 4,500 soldiers killed and 4,800 taken prisoner.^[1] Bodart asserted that the Austrians lost 3,000 killed and wounded, plus 500 captured. Their Bourbon opponents lost 7,000 killed and wounded, plus 3,000 captured. The following general officers were killed: French Mestres de camp Borstell and Comte Tessé, French Brigadier Marquis de Lescure, and Spanish Brigadiers Conde du Chais and Don Romei.^[3]

Louis-Joseph de Montcalm was one of them. Following the battle, the Bourbons evacuated Piacenza on June 27, and were shepherded eastwards by the Austro-Piedmontese armies into the Republic of Genoa.

The battle did not mark the end of the fighting in Italy and an attempt to exploit the victory by invading Provence at the end of the year ended in failure. As a result, the Austrians were released from the captured Genoa by a revolt in December, 1746.^[24]

Historian Reed Browning wrote, "Few would have suspected it that day, but in fact the question of domination in Lombardy had now been effectively answered for the next half century."^[1] Author Jeremy Black stated that the battle of Piacenza, "ended Bourbon hopes of overrunning northern Italy and set the territorial pattern of the peninsula until the French Revolutionary Wars."^[2]

• Black, Jeremy (2002). America Or Europe?: British Foreign Policy, 1739–63. Routledge. ISBN 978-1-135-36934-7. Retrieved 2015-06-07.
• Bodart, Gaston (1908). "Militär-historisches Kriegs-Lexikon (1618-1905)" (in German). Wien. p. 209. Retrieved 22 January 2026.
• Browning, Reed (1995). The War of the Austrian Succession. St. Martin's Press. ISBN 0-312-12561-5.
• Cust, Edward (1862). Annals of the Wars of the Eighteenth Century, 1739–1759. Vol. II. London: John Murray. OCLC 278260270. Retrieved 19 January 2026.
• Schmidt-Brentano, Antonio (2006). "Kaiserliche und k.k. Generale (1618-1815)" (in German). Österreichisches Staatsarchiv. Retrieved 16 January 2025. This source gives the full names, as well as birth, death, and promotion dates of Austrian generals.

• Acerbi, Enrico (2022). "Wargame: Piacenza 1746 - A crucial battle of the War of the Austrian Succession (1740 - 1748)". Europa Simulazioni. Retrieved 26 February 2026.

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