Orsini was a radical republican and a follower of Mazzini, who took part in the 1848 revolutions, served in the government of the Roman Republic in 1849 and led a plot to assassinate Napoleon III of Italy in 1858. Orsini was hoping that Napoleon’s death would cause another revolution in France, and that a revolutionary government would help Italy to get rid of the Austrians.
The Orsini Plot used British-made bombs which were thrown at Napoleon III’s carriage as he was on his way to the theatre in Paris on the 14th of January in 1858. Four bombs were thrown. Eight people were killed, one hundred and fifty were injured, but Napoleon and his wife were left untouched by the explosions.
Napoleon III decided to use the affair as an excuse to increase French influence in the Italian Peninsula, and, after a meeting with Cavour in Plombieres in July 1858, devised a plan to irritate Austria into declaring war on Piedmont, so that France could come to Piedmont’s aid and replace Austria as the dominant power in Italy.