Italo-Prussian Alliance
[1]: 3 [2] In January 1861, a few months before his death, Cavour sent Alfonso La Marmora to Berlin, officially to represent the Kingdom of Italy at the coronation of Kaiser Wilhelm I.
[5]: 56 In October 1865, Italian diplomacy took a final step to obtain the Veneto without bloodshed when La Marmora authorized Count Alessandro Malaguzzi Valeri to open secret negotiations with Austria, which was offered a large sum of money in exchange for the region.
At the end of July 1865 he had one of his diplomats, Karl von Usedom, ask Prime Minister La Marmora what attitude Italy would have in the event of an Austro-Prussian conflict.
[1]: 4 [3][5]: 60–61 Questioned about this on 13 August 1865 by the Italian ambassador in Paris Costantino Nigra, the French Foreign Minister Drouyn de Lhuys reported that France would remain neutral in the event of an Austro-Prussian war and would not oppose Italy's involvement on Prussia’s side.
However, to avoid the danger of Prussia being attacked in turn by neighbouring powers, he first had to make sure of Russia's neutral attitude and Great Britain's disinterest before consulting France.
[11] On 7 February, the Austrian Foreign Minister, Alexander von Mensdorff, in turn protested against Prussian interference in the administration of the Duchy of Holstein and against the unbearable climate created by Prussia.
In fact, the Chancellor first proposed a general treaty with Italy which, lacking any military specifics, seemed more suited to intimidating Austria in order to obtain advantages on the question of Schleswig and Holstein than anything else.
This was due to the fact that Bismarck’s plans were opposed at the court of Kaiser Wilhelm I,[1]: 5 [12]: 139–140 leaving him unable to immediately conclude a reciprocal military treaty with Italy, which was what La Marmora wanted.
[1]: 9–10 After having examined a draft of the treaty from Bismarck, on 28 March 1866, La Marmora telegraphed to his representative in Berlin Giulio De Barral[14] to communicate to him the favourable impression that the proposal had received in Florence.
The most significant was the proposal to cede Veneto to France (Austria officially had no relations with Italy) in exchange for French and Italian neutrality in the event of an Austro-Prussian conflict.
[4] La Marmora wanted to sound out Prussia's likely response in the event of a preventive Austrian attack on Italy, in order to be able to decide on Vienna's offer with greater peace of mind.
On 7 May, he received the reply from Ambassador De Barral that both Bismarck and William I, despite the treaty not explicitly providing for it, had given assurances that Prussia would come to Italy's aid in the event of an Austrian attack.
Napoleon III, evidently beginning to doubt the advantage to France from a war between Austria and Prussia, proposed to convene a European congress to try and resolve all of the current sources of tension: the Veneto, Schleswig-Holstein and the reform of the German Confederation.
[1]: 15 [16]: 141–2 On 12 June (the day of the agreement with France), Vienna broke off diplomatic relations with Berlin and on the 14th presented a motion to the German Diet for federal mobilization against Prussia.
Warned of the impending military catastrophe by General Benedek, the Austrian Emperor Franz Joseph I, during the night between 2 and 3 July 1866, thought of immediately and unconditionally offering the Veneto to Napoleon III in order to obtain an armistice with Italy.
[17]: 369–70 Napoleon III, who was beginning to seriously fear the consequences of a dramatic and decisive Prussian success,[1]: 28 telegraphed Victor Emmanuel II on 5 July offering him the Veneto in exchange for peace with Austria.
[8]: 71 For Prime Minister Ricasoli, outright refusal of French mediation was impossible but he played for time, continuing military operations with maximum energy for as long as possible.
Italy, however, was seeking a military victory and to Napoleon III's requests for peace it initially responded that it was waiting for direct official communication from its Prussian ally.
The Italian troops in Trentino commanded by Garibaldi and Medici were then recalled and on 12 August, at Cormons, the final armistice between Italy and Austria was concluded, followed on 3 October by the Peace of Vienna.
