This secret 1858 verbal accord between Cavour and Napoleon III laid the groundwork for the Franco-Piedmontese alliance and the Second Italian War of Independence, accelerating Italian unification.
Key Facts
- Date of meeting
- 21 July 1858
- Nature of agreement
- Secret verbal; nothing was signed
- Military alliance signed
- 28 January 1859
- Target of planned war
- Austria, to expel its influence from Italy
- Italian unification achieved
- Within a decade of the agreement
Location
Cause → Event → Consequence
Austria's dominant influence over the Italian peninsula blocked Piedmont-Sardinia's ambitions for Italian unification. Piedmont's chief minister Cavour sought a powerful military ally to confront Austria, while French Emperor Napoleon III harbored his own strategic and dynastic interests in reshaping the Italian political order and weakening Austrian power in Europe.
On 21 July 1858, Cavour and Napoleon III met secretly at the spa town of Plombières-les-Bains and reached a verbal agreement. They planned a future war in which France and Piedmont would jointly fight Austria to expel Austrian influence from Italy. In return, Italy would be reorganized into two spheres of influence dominated by Piedmont and France respectively.
The agreement directly produced the formal Franco-Piedmontese military alliance of 28 January 1859 and triggered the Second Italian War of Independence. Although the precise geopolitical outcome envisaged at Plombières was not realized, the war severely weakened Austrian power in Italy and became a decisive step toward achieving Italian unification within a decade.
Political Outcome
Secret accord to ally France and Piedmont against Austria, reorganizing Italy into two spheres of influence; led directly to the Franco-Piedmontese military alliance and the Second Italian War of Independence.
Austria held dominant influence over the Italian peninsula
Austrian influence removed from much of Italy; path opened for Italian unification under Piedmontese leadership