The Revolutions of 1848 saw a series of revolutions break out across Italy and Europe in early 1848. Many Italian states implemented new constitutions in response, including the kingdom of Piedmont-Sardinia which adopted a constitutional monarchy. Piedmont-Sardinia went to war with Austria over Italian possessions but lost, though the kingdom survived under Victor Emanuel II and became seen as a symbol of Italian unity. France sent troops to restore the Pope's rule in Rome and crush the newly declared Roman Republic led partly by Mazzini, and a soldier named Garibaldi became famous for defending Rome before the revolutionaries' retreat.