Plombières Agreement
In its place, Italy, which Klemens von Metternich, a previous Austrian chancellor, had reportedly dismissed on various occasions as a "[mere] geographical expression",[2] would be divided into two spheres of influence to be dominated respectively by Piedmont and France.
Actively supporting Italian nationalist aspirations would place France firmly on the side of what was then seen as progressive liberalism, and confirm the nation's special revolutionary credentials.
[4] The prime minister of Piedmont-Sardinia, Camillo Benso, Count of Cavour, was aware of the French objectives and was looking for an opportunity to serve these, while simultaneously achieving his goal of lifting the oppressive burden of Austrian rule from as many Italians as possible The arrival in Turin of Jacques Alexandre Bixio in April 1858 provided Cavour with his opportunity.
The agreement would be reinforced through the marriage of Princess Maria Clotilde of Savoy, daughter of the Piedmontese king, Victor Emmanuel II, to Prince Napoléon Bonaparte.
At this point, a suggestion came from the Emperor for a meeting between himself and Cavour at Plombières-les-Bains, a fashionable health resort in the small ravine of Augronne [fr] in the Vosges, reassuringly far from Paris or Turin, and off the beaten track of those following international diplomacy and politics.
Cavour's report takes the form of a letter that he wrote to the King on 24 July 1858 from an overnight halt at Baden-Baden, while on his way home.
[9] There was discussion of whether the presence of an Austrian military garrison in Bologna (in the Papal States) might justify war against Austria, but the French Emperor was in the end reluctant to use this as a pretext.
The king of Piedmont-Sardinia would respond by graciously declining the appeal in the terms in which it was put, but he would nevertheless send a threatening communication to Francis V of Modena.
Piedmont-Sardinia would then find itself obliged to occupy Massa, a coastal city and an important port belonging to the Duchy of Modena, by which time a wider war with Austria would have been triggered.
He highlighted the unfortunate rumours in circulation about the character of Prince Napoléon Bonaparte and also drew attention to the age of the Princess, who was only fifteen.
"[4][11] It appears from Cavour's report of the meeting that Napoleon III had prepared very carefully for it, and dictated the terms of the secret "Plombières Agreement" that resulted.
[4] Not everything agreed verbally at Plombières six months before surfaced in the treaty: it was silent on the geo-political understandings covering central and southern Italy.
Following a series of provocative military movements near the Austro-Piedmontese frontier by Piedmont-Sardinia, and having become aware of the Franco-Sardinian alliance, the Austrians took the initiative by issuing the Ultimatum of Vienna on 23 April 1859.
Napoleon III concluded that his earlier plan to secure French domination of central and southern Italy through his alliance with Piedmont-Sardinia could only be achieved at an unacceptable military and economic cost.
On a personal level, he seems to have been genuinely (and very publicly) horrified by the slaughter involved in fighting wars in an industrial age, notably at the battles of Magenta and Solferino.
He was also aware of the risk to French security from an ambitious and opportunistic Prussia in the event of France becoming over-committed militarily in Italy.
However, these central Italian territories were now occupied by Piedmontese troops who showed no enthusiasm for the idea of restoring Austrian-sponsored rulers.
