Austrian troops crossed the Po River on a reconnaissance-in-force and captured several Piedmontese-held strong points at Casteggio and Montebello. French troops checked this advance and drove the Austrians back onto Montebello where fierce fighting was decided by a stream of French reinforcements arriving by railway train from Voghera. The Battle of Montebello lost, the Austrians withdrew back across the Po. (By John Osborne)

Emperor Napoleon III left Paris in the charge of his wife, the Empress Eugenie, and traveled to Italy via Marseilles, arriving in Genoa two days later. There he took command of the French forces gathering in Italy to combat the Austrian invasion. The war would last seven months and end with a complete Franco-Italian victory. (By John Osborne)

The Count de Montemolin, a Carlist claimant to the Spanish throne of Isabella II, landed with 3,600 soldiers on the Spanish coast and began a march on Valencia. No-one had told the soldiers of their mission and when the rank-and-file discovered its purpose they immediately declared themselves loyal subjects of the Queen and arrested their leaders. Isabella showed mercy and merely deported her cousin. (By John Osborne)

Named as the Conservative president of the Republic, General Miguel Miramón led the forces of the military junta striving to defeat the constitutional Liberal government in Mexico. He reached and surrounded the Liberal capital of Vera Cruz on the Mexican coast in March. The Liberals sent their women and children away by ship and prepared to make a determined stand. Such Liberal resolution in Vera Cruz, as well as in nearby Alvarado, resulted in Miramón's withdrawal nine days later. (By John Osborne)

Named as the Conservative president of the Republic, General Miguel Miramón led the forces of the military junta striving to defeat the constitutional Liberal government in Mexico. He reached and surrounded the Liberal capital of Vera Cruz on the Mexican coast in March. The Liberals sent their women and children away by ship and prepared to make a determined stand. Such Liberal resolution in Vera Cruz, as well as in nearby Alvarado, resulted in Miramón's withdrawal nine days later. (By John Osborne)

With the Austrian invasion of Piedmont-Sardinia well underway and Vienna firmly established as the aggressor, Napoleon III declared war and a week later left Paris to lead his troops to the aid of the Italians. If fact, French troops had been on the move for more than ten days and already had arrived by train in Milan and by ship in Genoa. The war would last seven months and end with a complete Franco-Italian victory. (By John Osborne)

Completing the difficult crossing of the swollen Ticino River over five days, five Austrian army corps under General Franz Gyulai extended their line across northern Italy almost without opposition. The Austrians were hoping for a swift victory over Piedmont-Sardinia before French troops could arrive to assist but continued rain and flooding would slow their advance. (By John Osborne)

For decades, the fiercely pro-Austrian Grand Duke Francesco V had been dependent on Austrian support to continue his reactionary rule of Modena. With much of his duchy under already under Piedmontese military occupation since May, he left for the Austrian lines. A provisional government was formed and Modena soon became part of a newly united Italy. (By John Osborne)

With war looming between Piedmont, France, and the Austrian Empire, nationalist street demonstrations erupted all over Italy. In Tuscany, the pro-Austrian Grand Duke Leopold was immediately under pressure and when, on this day, demonstrators in the Piazza Santa Maria Antonia in Florence were joined by Tuscan soldiers, he fled the city. A provisional government was formed and following the defeat of Austria Tuscany became part of a newly united Italy. (By John Osborne)