Nationalism was developed by conservatives, liberals and radicals who believed that the leaders of the nation should be the people and not a king or empire. Italy eventually united and took upon nationalism after many battles and conquerings. Until 1848, unification was only an idea and a hope of many people. During this time, significant political changes were occuring in Italy.
Giuseppe Mazzini was an Italian Nationalist who published writings attempting to unify Italy. One major idea he publicized was the concept of having a central democratic republic that was based primarily on following the will of the people as well as universal male suffrage, which included the right for all men to vote. Initially, the plan was for Italy to unite but remain under the power and influence of the Pope. Along with this, Piedmont-Sardinia, a large Kingdom in Italy, wanted to expand and create one large unified Kingdom in Italy with civil liberties, similar to what existed in Prussia. This last idea pushed by Piedmont-Sardinia was actually liked by many as it was not too radical but advocated for a unified Italy with a constitution allowing civil liberties.
Camillo di Cavour, Count of Cavour, was appointed by the King of Sardinia in 1848 to be the Prime Minister of Piedmont-Sardinia and unite Northern and Southern Italy. Cavour joined with Giuseppe Garibaldi and his Red Shirt Guerilla Band to free Southern Italy, including the Island of Sicily and the Southern part of Sicily. After taking Palermo, Naples and the remaining Southern Italy from Sicily, Garibaldi, Cavour and the people fighting for the unification annexed North and South of Italy into one country. Meanwhile, through Cavour’s strength in war and thoughtful tactics, he successfully removed Austria from controlling Northern Italy and united Northern and Southern Italy under a nationalist rule with Rome as the Capital.
The Vatican City however remained separate under the control of the Pope. This movement mainly spread because the people were fed up with a monarchy and one absolutist leader so when the people of Italy heard about Nationalism, they were excited to have another form of government running their united, independent country