Born in Turin as the eldest son of Charles Albert, Prince of Carignano, and Maria Theresa of Austria, Victor Emmanuel fought in the First Italian War of Independence (1848–1849) before being made King of Sardinia following his father's abdication.

In 1855, he sent an expeditionary corps to side with French and British forces during the Crimean War; the deployment of Italian troops to the Crimea, and the gallantry shown by them in the Battle of the Chernaya (16 August 1855) and in the siege of Sevastopol led the Kingdom of Sardinia to be among the participants at the peace conference at the end of the war, where it could address the issue of the Italian unification to other European powers.

In 1870, Victor Emmanuel also took advantage of the Prussian victory over France in the Franco-Prussian War to conquer the Papal States after the French withdrew.

He took part in the First Italian War of Independence (1848–1849) under his father, King Charles Albert, fighting in the front line at the battles of Pastrengo, Santa Lucia, Goito and Custoza.

The treaty, however, was not ratified by the Piedmontese lower parliamentary house, the Chamber of Deputies, and Victor Emmanuel retaliated by firing his Prime Minister, Claudio Gabriele de Launay, replacing him with Massimo D'Azeglio.

He applied liberalism and nationalism to dismantle the traditional structures of the Kingdom of Sardinia while advancing an anti-clerical agenda that started during Charles Albert.

Cavour was reluctant to go to war due to the power of Russia at the time and the expense of doing so; however, Victor Emmanuel was convinced of the rewards to be gained from the alliance created with Britain and more importantly France.

After successfully seeking British support and ingratiating himself with France and Napoleon III at the Congress of Paris in 1856 at the end of the war, Count Cavour arranged a secret meeting with the French emperor.

In 1858, they met at Plombières-les-Bains (in Lorraine), where they agreed that if the French were to help Piedmont in its war against Austria, which still reigned over the Kingdom of Lombardy–Venetia in northern Italy, France would be awarded Nice and Savoy.

France did not as a result receive the promised Nice and Savoy but Austria kept Venetia, a major setback for the Piedmontese, in no small part because the treaty had been prepared without their knowledge.

France only gained Nice and Savoy after the Treaty of Turin was signed in March 1860, after Cavour had been reinstalled as Prime Minister, and a deal with the French was struck for plebiscites to take place in the Central Italian Duchies.

The British Foreign Secretary, Lord Clarendon, visited Florence in December 1867 and reported to London after talking to various Italian politicians: "There is universal agreement that Victor Emmanuel is an imbecile; he is a dishonest man who tells lies to everyone; at this rate, he will end up losing his crown and ruining both Italy and his dynasty.

"[4] In 1870, after two failed attempts by Garibaldi, he also took advantage of the Prussian victory over France in the Franco-Prussian War to capture Rome after the French withdrew.

Despite this mishap, the remainder of Victor Emmanuel II's reign was consumed by wrapping up loose ends and dealing with economic and cultural issues.