Plombières Agreement

The Plombières Agreement was a secret pact made in July 1858 between French Emperor Napoleon III and Piedmontese Prime Minister Count Cavour. This agreement was a crucial step towards the unification of Italy.1

The plan outlined at Plombières involved France aiding Piedmont in a war against Austria to gain control of Lombardy and Venetia. In return, Piedmont would cede Savoy and Nice to France. This alliance was intended to create a northern Italian kingdom under Piedmontese leadership. However, Napoleon III unexpectedly made a separate peace with Austria at the Conference of Villafranca in July 1859, after the Battle of Solferino. This preliminary peace gave Lombardy to Piedmont but kept Venetia under Austrian control and aimed to restore rulers to central Italian duchies. This outcome frustrated Italian nationalists and Cavour, who resigned in protest, though he later returned to office and pursued unification through other means.21