Piedmontese lawyer and statesman who held many important cabinet positions in the early years of the Italian Republic, including that of prime minister; his ambiguous policies brought him into conflict with the Italian hero Giuseppe Garibaldi (Garibaldi, Giuseppe) and ultimately caused his downfall.

In 1848 Rattazzi was elected deputy to the Sardinian Parliament. For the next decade he held various ministerial positions and became associated with the brilliant premier Count Cavour. Violently anticlerical and considered devoid of principle, Rattazzi nevertheless became premier after Cavour's death. At this time Garibaldi offered to capture Rome, then occupied by the French. Rattazzi at first sanctioned this venture and then changed his mind and sent troops to intercept Garibaldi, who was wounded in the ensuing Battle of Aspromonte (1862). Public opinion condemning this action forced Rattazzi's resignation.

In 1867 Rattazzi was again asked to be premier, and again Garibaldi marched on Rome, with Rattazzi's tacit consent. Rattazzi once more changed his mind, and he ordered Garibaldi arrested. Faced with the choice of arresting Garibaldi's volunteers or invading Rome himself, Rattazzi resigned.