There have been several distinct entities known as the Kingdom of Italy. Italy under the rule of Odoacer

Odoacer

Flavius Odoacer , also known as Flavius Odovacer, was the first King of Italy. His reign is commonly seen as marking the end of the Western Roman Empire. Though the real power in Italy was in his hands, he represented himself as the client of Julius Nepos and, after Nepos' death in 480, of the...

 from 476 to 493 is often called the Kingdom of Italy, since it encompassed the Roman province of Italy and Odoacer is periodically (though always unofficially) styled rex (king). The Ostrogothic Kingdom

Ostrogothic Kingdom

The Kingdom established by the Ostrogoths in Italy and neighbouring areas lasted from 493 to 553. In Italy the Ostrogoths replaced Odoacer, the de facto ruler of Italy who had deposed the last emperor of the Western Roman Empire in 476. The Gothic kingdom reached its zenith under the rule of its...

 that replaced Odoacer's rule in Italy is also sometimes referred to as a "kingdom of Italy". The term rex Italiae (king of Italy) came into use with the Ostrogoths. The other kingdoms of Italy were more formal:

• Kingdom of Italy (medieval)
  Kingdom of Italy (medieval)
  The Kingdom of Italy was a political entity under control of Carolingian dynasty of Francia first, after the defeat of the Lombards in 774. It was finally incorporated as a part of the Holy Roman Empire in 962....
  
  

A state established by the Lombards

Lombards

The Lombards , also referred to as Longobards, were a Germanic tribe of Scandinavian origin, who from 568 to 774 ruled a Kingdom in Italy...

 in 568 after they invaded and conquered much of the northern and central parts of the Italian peninsula. It was conquered by the Franks

Franks

The Franks were a confederation of Germanic tribes first attested in the third century AD as living north and east of the Lower Rhine River. From the third to fifth centuries some Franks raided Roman territory while other Franks joined the Roman troops in Gaul. Only the Salian Franks formed a...

 in 774 and formed a part of the Carolingian Empire

Carolingian Empire

Carolingian Empire is a historiographical term which has been used to refer to the realm of the Franks under the Carolingian dynasty in the Early Middle Ages. This dynasty is seen as the founders of France and Germany, and its beginning date is based on the crowning of Charlemagne, or Charles the...

 and Middle Francia

Middle Francia

Middle Francia was an ephemeral Frankish kingdom created by the Treaty of Verdun in 843, which divided the Carolingian Empire among the sons of Louis the Pious...

, but always with its own kings. It enjoyed a period of independence from any higher authority after the fall of Carolingian Empire until Otto the Great, already King of Germany, inherited its throne, a formative moment in the history of the Holy Roman Empire

Holy Roman Empire

The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

. Thereafter the kingdom was tethered to Germany as a part of the Empire, but its importance as a separate polity declined in the High Middle Ages

High Middle Ages

The High Middle Ages was the period of European history around the 11th, 12th, and 13th centuries . The High Middle Ages were preceded by the Early Middle Ages and followed by the Late Middle Ages, which by convention end around 1500....

 and by the Renaissance

Renaissance

The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 it had ceased to function, though it had a nominal existence until the dissolution of the Empire in 1806.

• Kingdom of Italy (Napoleonic)
  Kingdom of Italy (Napoleonic)
  The Kingdom of Italy was a state founded in Northern Italy by Napoleon, fully influenced by revolutionary France, that ended with his defeat and fall.-Constitutional statutes:...
  
  

Napoleon Bonaparte established a French client state in Italy between 1805 and 1814.

• Kingdom of Italy (1861–1946)
  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...
  
  

Following the unification of Italy

Italian unification

Italian unification was the political and social movement that agglomerated different states of the Italian peninsula into the single state of Italy in the 19th century...

 under the leadership of Giuseppe Garibaldi

Giuseppe Garibaldi

Giuseppe Garibaldi was an Italian military and political figure. In his twenties, he joined the Carbonari Italian patriot revolutionaries, and fled Italy after a failed insurrection. Garibaldi took part in the War of the Farrapos and the Uruguayan Civil War leading the Italian Legion, and...

, the House of Savoy

House of Savoy

The House of Savoy was formed in the early 11th century in the historical Savoy region. Through gradual expansion, it grew from ruling a small county in that region to eventually rule the Kingdom of Italy from 1861 until the end of World War II, king of Croatia and King of Armenia...

, then represented by Victor Emmanuel II

Victor Emmanuel II of Italy

Victor Emanuel II was king of Sardinia from 1849 and, on 17 March 1861, he assumed the title King of Italy to become the first king of a united Italy since the 6th century, a title he held until his death in 1878...

, was invited to hold the throne of a new independent kingdom in 1861. The state was often known as Fascist Italy

Fascist Italy

"Fascist Italy" refers to Italy under the rule of Benito Mussolini and Italian Fascism. The Fascists led two polities:*The Kingdom of Italy , under the National Fascist Party, and,...

 during the regime of Benito Mussolini

Benito Mussolini

Benito Amilcare Andrea Mussolini was an Italian politician who led the National Fascist Party and is credited with being one of the key figures in the creation of Fascism....

 from 1922 to 1943. In the northern and central parts of the kingdom of Italy, the Italian Social Republic

Italian Social Republic

The Italian Social Republic was a puppet state of Nazi Germany led by the "Duce of the Nation" and "Minister of Foreign Affairs" Benito Mussolini and his Republican Fascist Party. The RSI exercised nominal sovereignty in northern Italy but was largely dependent on the Wehrmacht to maintain control...

 claimed sovereignty and jurisdiction for a short time from 1943 until 1945. The kingdom of Italy continued to exist in the liberated parts of central and southern Italy but was replaced by a republic in 1946.