As a result of the Austro-Sardinian War of 1859, Sardinia-Piedmont annexed Lombardy, while Giuseppe Garibaldi overthrew the Bourbon monarchy in the south. Afraid that Garibaldi would set up a republican government, the Piedmont government petitioned French Emperor Napoleon III for permission to send troops through the Papal States to gain control of the south. This was granted on the condition that Rome be left undisturbed.