Second Italian War of Independence The Second Italian War of Independence , also called the Austro - Sardinian War or Austro - Piedmontese War , was fought by the Second French Empire and the Kingdom of Sardinia against the Austrian Empire in 1859 and was a key event in the process of Italian unification . Background . The Piedmontese , following their defeat to Austria in the First Italian War of Independence , found that they could not defeat a great power such as Austria without allies . This led Camillo Benso , conte di Cavour to attempt to establish relations with other European powers , partially through Piedmont ' s participation in the Crimean War . In the peace conference at Paris for the Crimean War , Cavour attempted to bring attention to efforts for Italian unification . He found Britain and France to be sympathetic , but entirely unwilling to go against Austrian wishes , as any movement towards Italian independence would necessarily threaten Austria ' s territory in Lombardy and Venetia . Individual talks between Napoleon III and Cavour after the conference identified Napoleon as the most likely , albeit still uncommitted , candidate for aiding Italy . On January 14 , 1858 , Felice Orsini , an Italian , led an attempt on Napoleon III ' s life . This assassination attempt brought widespread sympathy for the Italian unification effort , and had a profound effect on Napoleon himself , who now was determined to help Piedmont against Austria in order to end the revolutionary activities that the governments inside Italy might allow to happen in the future . Emperor Napoleon III and Camillo Benso , Conte di Cavour , the prime minister of the Kingdom of Piedmont - Sardinia , signed a secret treaty of alliance against Austria : France would help Sardinia to fight against Austria if attacked , and Sardinia would then give Nice and Savoy to France in return . This secret alliance served both countries : it helped with the Sardinian ( Piedmontese ) plan of unification of the Italian peninsula under the House of Savoy , and weakened Austria , a fiery adversary of Napoleon III ' s French Empire . Cavour , being unable to get the French help unless the Austrians attacked first , provoked Vienna with a series of military manoeuvers close to the border . Austria issued an ultimatum on April 23 , 1859 , asking for the complete demobilization of the Sardinian army , and when it was not heeded Austria started a war with Sardinia ( April 29 ) , thus drawing France into the conflict . Forces . The French army for the Italian campaign had 170 , 000 soldiers , 2 , 000 horsemen and 312 guns , half of the whole French army . The army was under the command of Napoleon III , divided into five corps : the I Corps , led by Achille Baraguey d ' Hilliers , the II , led by Patrice MacMahon , the III , led by François Certain Canrobert , the IV , led by Adolphe Niel , and the V , led by prince Napoleon . The Imperial Guard was commanded by Auguste Regnaud de Saint - Jean d ' Angély . The Sardinian army had about 70 , 000 soldiers , 4 , 000 horsemen and 90 guns . It was divided into five divisions , led by Casterlbrugo , Manfredo Fanti , Giovanni Durando , Enrico Cialdini , and Domenico Cucchiari . Two volunteers formations , the Cacciatori delle Alpi and the Cacciatori degli Appennini , were also present . The commander in chief was Victor Emmanuel II of Savoy , supported by Alfonso Ferrero la Marmora . The Austrian army fielded more men : it was composed by 220 , 000 soldiers , 824 guns and 22 , 000 horsemen . It was led by Field Marshal Ferenc " Graf " Gyulay . The operations . At the declaration of war , there were no French troops in Italy , so Marshal François Certain Canrobert moved into Piedmont in the first massive use of railways . The Austrian forces counted on a swift victory over the weaker Sardinian army before French forces could arrive in Piedmont . However , Count Gyulai , the commander of the Austrian troops in Lombardy , was very cautious , marching around the Ticino River in no specific direction for a while until eventually crossing it to begin the offensive . Unfortunately for him , very heavy rains began to fall as soon as he did this , allowing the Piedmontese to flood the rice fields in front of his advance , slowing his army ' s march to a crawl . The Austrians under Gyulai eventually arrived in Vercelli , menacing Turin , but the Franco - Sardinian move to strengthen Alessandria and Po River bridges around Casale Monferrato forced them to fall back . On May 14 , Napoleon III arrived in Alessandria , taking the command of the operations . The initial clash of the war was at Montebello on 20 May , a battle between an Austrian Corps under Stadion and a single division of the French I Corps under Forey . The Austrian contingent was three times as large , but the French were victorious , making Gyulai still more cautious . In early June , Gyulai had advanced to the rail center of Magenta , leaving his army spread out . Napoleon III attacked the Ticino head on with part of his force while sending another large group of troops to the north to flank the Austrians . The plan worked , causing Gyulai to retreat east to the quadrilateral fortresses in Lombardy , where he was relieved of his post as commander . Replacing Gyulai was Emperor Franz Josef I himself . He planned to defend the well - fortified Austrian territory behind the Mincio River . The Piedmontese - French army had taken Milan and slowly marched further east to finish off Austria in this war before Prussia could get involved . The Austrians found out that the French had halted at Brescia , and decided that they should counterattack along the river Chiese . The two armies met accidentally around Solferino , precipitating a confused series of battles . A French corps held off three Austrian corps all day at Medole , keeping them from joining the larger battle around Solferino , where , after a day - long battle , the French broke through . Ludwig von Benedek with the Austrian VIII Corps was separated from the main force , defended Pozzolengo against the Piedmontese part of the opposing army . This they did successfully , but the entire Austrian army retreated after the breakthrough at Solferino , withdrawing back into the Quadrilateral . At the same time , in the northern part of Lombardy , the Italian volunteers of Giuseppe Garibaldi ' s " Hunters of the Alps " defeated the Austrians at Varese and Como and the Piedmontese - French navy landed 3 , 000 soldiers and conquered the islands of Losinj ( Lussino ) and Cres ( Cherso ) in Dalmatia . The peace . Fear of involvement by the German states led Napoleon to seek a way out of the war , so he signed an armistice with Austria in Villafranca . Most of Lombardy , with its capital Milan ( excepting only the Austrian fortresses of Mantua and Legnago and the surrounding territory ) , was transferred from Austria to France , which would immediately cede these territories to Sardinia . The rulers of Central Italy , who had been expelled by revolution shortly after the beginning of the war , were to be restored . This deal , made by Napoleon behind the backs of his Sardinian allies , led to great outrage in Sardinia — Cavour himself resigned in protest . However , the terms of Villafranca were never to come into effect : although they were reaffirmed by the final Treaty of Zürich in November , by then the agreement had become a dead letter . The central Italian states were occupied by the Piedmontese , who showed no willingness to restore the previous rulers , and the French showed no willingness to force them to abide by the terms of the treaty . The Austrians were left to look on in frustration at the French failure to carry out the terms of the treaty . The next year , in 1860 , with French and British approval , the central Italian states — Duchy of Parma , Duchy of Modena , Grand Duchy of Tuscany and the Papal Legations — were annexed by the Kingdom of Sardinia , and France would take its deferred reward , Savoy and Nice . This latter move was vehemently opposed by Italian national hero Garibaldi , a native of Nice , and directly led to Garibaldi ' s expedition to Sicily , which would complete the preliminary unification of Italy .