Italian unification was the political and social movement that agglomerated different states of the Italian peninsula

Italian Peninsula

The Italian Peninsula or Apennine Peninsula is one of the three large peninsulas of Southern Europe , spanning from the Po Valley in the north to the central Mediterranean Sea in the south. The peninsula's shape gives it the nickname Lo Stivale...

 into the single state of Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 in the 19th century. Despite a lack of consensus on the exact dates for the beginning and end of this period, many scholars agree that the process began in 1815 with the Congress of Vienna

Congress of Vienna

The Congress of Vienna was a conference of ambassadors of European states chaired by Klemens Wenzel von Metternich, and held in Vienna from September, 1814 to June, 1815. The objective of the Congress was to settle the many issues arising from the French Revolutionary Wars, the Napoleonic Wars,...

 and the end of Napoleonic

Napoleon I of France

Napoleon Bonaparte was a French military and political leader during the latter stages of the French Revolution.As Napoleon I, he was Emperor of the French from 1804 to 1815...

 rule, and ended in 1871 with the Franco-Prussian War

Franco-Prussian War

The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...

. The last città irredente

Italia irredenta

Italian irredentism was an Italian Irredentist movement that aimed at the unification of all ethnically Italian peoples....

however, did not join the Kingdom of Italy

Kingdom of Italy (1861–1946)

The Kingdom of Italy was a state forged in 1861 by the unification of Italy under the influence of the Kingdom of Sardinia, which was its legal predecessor state...

 until after World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

.
After the fall of the Western Roman Empire

Western Roman Empire

The Western Roman Empire was the western half of the Roman Empire after its division by Diocletian in 285; the other half of the Roman Empire was the Eastern Roman Empire, commonly referred to today as the Byzantine Empire....

, Italy gradually developed into a system of city-states

Italian city-states

The Italian city-states were a political phenomenon of small independent states mostly in the central and northern Italian peninsula between the 10th and 15th centuries....

.