Why did Italy go to war in 1866?
Italy could not take Venetia from Austria by itself. It needed a great power to fight beside it. In 1866 one appeared: Prussia, the strongest state in north Germany. Its chief minister, Otto von Bismarck, wanted a war to push Austria out of German affairs. If Austria had to fight in the north and the south at the same time, its army would be split. So Bismarck wanted Italy, and Italy wanted Venetia.
On 8 April 1866 the two countries signed a secret alliance. Its terms were simple:
- If Prussia went to war with Austria within three months, Italy would attack Austria too.
- Neither country would make peace without the other.
- Italy's reward would be Venetia.
Napoleon III encouraged Italy to sign. He expected a long war that would weaken both German powers and leave France stronger.
Austria now tried to buy Italy off. In May 1866 it offered to give up Venetia if Italy stayed out of the war. The prime minister, General La Marmora, refused. Italy had given its word to Prussia, and many Italians wanted to win Venetia by fighting, not as a gift. In June, Austria made a secret deal with Napoleon III instead. It promised to hand Venetia to France, to be passed on to Italy, if France stayed neutral. So before a shot was fired, Italy was almost certain to get Venetia whatever happened. War began in mid-June, and Italy declared war on Austria on 20 June 1866.
The spec calls this 'Piedmont and the Austro-Prussian War', but by 1866 the state that fought was the Kingdom of Italy.
Key terms:
- Austro-Prussian War: the war of June to August 1866 between Austria and Prussia, also called the Seven Weeks' War.
- Third War of Independence: the Italian name for Italy's part in that war.
- Cede: to hand over land to another country, usually in a treaty.
The second battle of Custoza, 24 June 1866
On paper Italy should have won. It put about 200,000 men in the field against about 75,000 Austrians in Venetia. But the army was badly led. Victor Emmanuel II was commander in name, and his two leading generals disliked each other and could not agree on a plan. So the army was split in two. La Marmora, who had resigned as prime minister to act as chief of staff, led the larger part across the River Mincio from the west. General Cialdini waited with the rest on the lower River Po, far to the south.
La Marmora did not know where the Austrians were. On 24 June his spread-out columns walked into the army of Archduke Albert on the hills around Custoza. This was the same place where Piedmont had been beaten in 1848, which is why it is called the second battle of Custoza. (The spec spells it 'Custozza'.)
The fighting was confused and lasted all day. Only part of La Marmora's force ever got into the battle, and Cialdini's men took no part at all. By evening the Italians had been pushed off the hills. Fewer than 1,000 Italian soldiers had been killed, and the Austrians had lost more men killed and wounded than the Italians had. The army was far from destroyed. But La Marmora lost his nerve and ordered a retreat back across the Mincio. Cialdini pulled back as well. A setback had been turned into a humiliating defeat.
Defeat at sea, success in the mountains
⚓ Lissa, 20 July 1866
The Italian navy was bigger and newer than Austria's. Even so, Admiral Persano was beaten by a smaller Austrian fleet near the island of Lissa in the Adriatic Sea. Italy lost two of its iron-armoured warships. Persano was later put on trial and dismissed from the navy.
⛰ Garibaldi in the Trentino
Only Garibaldi brought good news. His volunteers pushed into the Trentino, the Italian-speaking mountain region north of Venetia, and won at Bezzecca on 21 July. Then peace talks began and he was ordered to pull out. His reply was a telegram of one word: 'Obbedisco' ('I obey').
How was Venetia won?
Venetia was won in Germany, not in Italy. On 3 July 1866 the Prussian army crushed the main Austrian army at Königgrätz (also called Sadowa). Austria had in effect lost the war in a single day. Within days it ceded Venetia to Napoleon III and asked him to arrange peace.
Italy had helped. Its army had kept tens of thousands of Austrian soldiers in Venetia, far away from Königgrätz. But Bismarck had what he wanted, and on 26 July he agreed peace terms with Austria without waiting for Italy. Italy could not fight Austria alone, so it signed an armistice on 12 August.
The Treaty of Vienna (3 October 1866) ended the war between Italy and Austria. The way Venetia changed hands hurt Italian pride:
- Austria would not give Venetia straight to a country it had beaten. It gave it to France.
- On 19 October a French general handed the region over in a hotel room in Venice.
- A plebiscite on 21-22 October gave about 647,000 votes for union with Italy and only 69 against.
- Victor Emmanuel II entered Venice on 7 November 1866.
Why did the union with Venetia matter?
📈 What Italy gained
Venetia and the fortress city of Mantua joined the kingdom. Austrian rule in the Italian peninsula, the biggest barrier to unity since 1815, was over. Only Rome was now missing.
📉 What it cost
Italy had been given Venetia by Prussia's victory and French diplomacy, not by its own strength. Custoza and Lissa damaged the reputation of the king, the generals and the navy. The Trentino and the port of Trieste, where many Italians lived, stayed Austrian. The war was also very expensive for a state already deep in debt.
So 1866 repeated the pattern of 1859. Italy grew because a foreign great power beat Austria. Many Italians felt that their new state had failed its first real test.
Common mistakes
- Saying Italy won Venetia by defeating Austria. Italy lost at Custoza and Lissa. Prussia's victory at Königgrätz won Venetia.
- Mixing up the two battles of Custoza. The first was in 1848, the second on 24 June 1866.
- Writing that Austria gave Venetia to Italy. Austria ceded it to France, and France passed it on.
Exam-style question
Extract A (a practice extract written for this lesson, in the style of a modern history book)
From a modern history textbook.
Italy's war of 1866 was a sorry affair. Its generals, more interested in their own quarrels than in the enemy, threw away a huge advantage in numbers at Custoza and fled from a battle that was far from lost. At Lissa the navy managed to lose to a smaller fleet. Venetia was finally tossed to Italy like a tip to a waiter, passed on by a French general in a hotel room. Italians had dreamed of winning Venice in glory. They were handed it in shame.
What impression does the author give about the way Italy gained Venetia in 1866? You must use Extract A to explain your answer. [6 marks]
Model answer
The author gives the impression that Italy gained Venetia in a humiliating way and did not deserve it. This is shown by the loaded language. The war is called 'a sorry affair', and the generals 'threw away' their advantage and 'fled', which makes them sound careless and cowardly. The comparison 'tossed to Italy like a tip to a waiter' suggests Italy was treated as a servant, not as a great power. The author ends on the word 'shame' and sets it against 'glory' to stress the gap between hopes and results. The author has also chosen to write only about failures. Nothing is said about Garibaldi's success in the Trentino or about how Italy helped Prussia by keeping Austrian troops in the south. This selection makes the gain of Venetia look like a disgrace.
What lifts it to the top level: it names one clear impression, proves it with short quotations, and explains how the author's choice of words and of what to leave out creates that impression.
Exam tip
Do not retell what the extract says about Custoza and Lissa. Pick out two or three of the author's words, such as 'fled' or 'shame', and say what each one suggests. Then add one line on what the author has left out. For more help, see the Exam Skills lesson 'Paper 1 Question (a): What Impression Does the Author Give?'.