Italian Independence wars: In the Battle of Magenta, the French army, under Louis-Napoleon, defeat the Austrian army.

The Battle of Magenta was fought on 4 June 1859 during the Second Italian War of Independence, resulting in a French-Sardinian victory under Napoleon III against the Austrians under Marshal Ferencz Gyulai.

It took place near the town of Magenta in the Kingdom of LombardyVenetia, a crown land of the Austrian Empire, on 4 June 1859. Napoleon III's army crossed the Ticino River and outflanked the Austrian right forcing the Austrian army under Gyulai to retreat. The confined nature of the country, a vast spread of orchards cut up by streams and irrigation canals, precluded elaborate manoeuvre. The Austrians turned every house into a miniature fortress. The brunt of the fighting was borne by 5,000 grenadiers of the French Imperial Guard, still mostly in their First Empire style of uniforms. The battle of Magenta was not a particularly large battle, but it was a decisive victory for the Franco-Sardinian alliance. Patrice de MacMahon was created Duc de Magenta for his role in this battle, and would later go on to serve as President of the French Third Republic.

An overwhelming majority of the French-Piedmontese coalition soldiers were French (1,100 were Piedmontese and 58,000 were French).

The Second Italian War of Independence, also called the Franco-Austrian War, the Austro-Sardinian War or Italian War of 1859 (Italian: Seconda guerra d'indipendenza italiana; French: Campagne d'Italie), was fought by the Second French Empire and the Savoyard Kingdom of Sardinia against the Austrian Empire in 1859 and played a crucial part in the process of Italian Unification.

A year prior to the war, in the Plombières Agreement, France agreed to support Sardinia's efforts to expel Austria from Italy in return for territorial compensation in the form of the Duchy of Savoy and the County of Nice. The two states signed a military alliance in January 1859. Sardinia mobilised its army on 9 March 1859, and Austria mobilized on 9 April.

On 23 April, Austria delivered an ultimatum to Sardinia demanding its demobilization. Upon Sardinia's refusal, the war began on 26 April. Austria invaded Sardinia three days later, and France declared war on Austria on 3 May.

The Austrian invasion was stopped by the arrival of French troops in Piedmont that had begun in late April. The Austrians were defeated at the Battle of Magenta on 4 June and pushed back to Lombardy, where the Franco-Sardinian victory at the Battle of Solferino on 24 June resulted in the end of the war and the signing of the Armistice of Villafranca on 12 July.

Austria ceded Lombardy to France, which, in turn, gave it to Sardinia. Exploiting the collapse of Austrian power in Italy, Sardinia annexed the United Provinces of Central Italy, consisting of the Grand Duchy of Tuscany, the Duchy of Parma, the Duchy of Modena and Reggio and the Papal Legations, on 22 March 1860. Two days later, Sardinia ceded Savoy and Nice to France at the Treaty of Turin as compensation for its assistance.