He was encouraged to become a priest, but he abandoned that lifestyle and became an ardent liberal, joining the Giovane Italia, a political society founded by Giuseppe Mazzini.

The new pope, Pius IX set him free, and he led a company of young Romagnols in the First War of Italian Independence in 1848, distinguishing himself in the engagements at Treviso and Vicenza.

[1] Orsini was elected member of the Roman Constituent Assembly in 1849, and after the fall of the revolutionary republic in Rome, he conspired against the papal autocracy in the interest of the Mazzinian party.

[1] He escaped a few months later using a tiny saw to cut through two grids of bars, climbed out of the window 100 feet above ground and slid down using a rope he had made of bedsheets.

[1] Orsini became convinced that Napoleon III was the chief obstacle to Italian independence and the principal cause of the anti-liberal reaction throughout Europe.

Satisfied, Orsini returned to Paris with the bombs and contacted other conspirators, Giovanni Andrea Pieri, Antonio Gomez and Carlo di Rudio (later changed to Charles DeRudio).

On the evening of 14 January 1858, as the Emperor and Empress were on their way to the theatre in the Rue Le Peletier, the precursor of the Opera Garnier, to see Rossini's William Tell, Orsini and his accomplices threw three bombs at the imperial carriage.