The revolution broke out in Venice on March 17, 1848, and proclaimed the republic of San Marco constitute a provisional government led by Daniele Manin.
The day after the revolution broke out in Milan, where he wanted the provisional regency of Lombardy and Veneto, the immediate election of a national representation, the Civic Guard. It gave rise to the five days (from March 18 to 22), during which the Milanese liberarorono the city by the Austrians, however, creating a political atmosphere full of contrasts between Democrats and moderates. This Panomara broke the first war of independence against the Austria. Was begun by Carlo Alberto of Savoy, on March 23, 1848: it was a war 'federalist' until all'allocuzione papal of 29 April 1848, 'Savoy' by 'allocution armistice Salasco (9 August 1848). The Italian won in Monzambano, Valeggio, Patrengo and Goito, managed to occupy Peschiera.
The defeat (at Custoza) was after Carlo Alberto had refused offers Austrian peace, rather than lose Venice and ducats emiliani. Savoy forces were forced to leave Milan in the hands of Radetzky. It was the armistice Salasco to close this first phase of the first war of independence. From August 1848 to February 1849 they were carried out the 'people's war' in Bologna, Osoppo, Venice, Florence and Rome.
The resumption of the war took place in March 20 of 1849, the Piedmontese army led by General Chrzanowski and little noise, was soon defeated at Novara. With the armistice of Vignale closed the second phase of the first war of independence lasting sol three days (20-23 March). Peace talks with the Radetzky were led by Vittorio Emanuele II, successor to his father Carlo Alberto, who abdicated and went into exile, and ended with the Peace of Milan. Nell 'in April of 1849 the advanced French and Spanish in Rome forced the Pope Pius IX, the defense of the city. The Patriots won in Palestrina, Velletri, Porta San Pancrazio, but opponents bought land forcing the combatants to cease fighting. Along this same line raises the defense of Venice broke out after the failure to Piedmont Novara. Austrians began the attack of Marghera, which was reduced to a pile of rubble (23 August 1849), but the real cause of the defeat of 'army were the fame, cholera and bombs. The main causes of this period were: the fragility of the domestic front, the hostile attitude of Europe, the incorrect assessment of the actual value of deficiencies of the General Staff of Savoy and the antagonism between moderates and democrats.