Second Italian War of Independence

The Second Italian War of Independence was fought in 1859, when the Kingdom of Sardinia-Piedmont, having secured a secret alliance with Emperor Napoleon III of France at the Plombieres Agreement, provoked Austria into declaring war so that France could intervene on its side. The allied Franco-Piedmontese armies defeated Austrian forces at the battles of Magenta and Solferino, the latter a notably bloody engagement whose scale later inspired the founding of the International Committee of the Red Cross. Napoleon III, alarmed by the war's cost and by Prussian mobilization on France's border, unexpectedly agreed to a separate peace with Austria at Villafranca before Piedmont's aims were fully achieved, but the war still led to the annexation of Lombardy to Piedmont and touched off a wave of plebiscites that brought most of central Italy into the growing Italian state over the following year.