The Kingdom of Naples (Regnum Neapolitanum; Regno di Napoli; Regno 'e Napule), also known as the Kingdom of Sicily, was a state that ruled the part of the Italian Peninsula south of the Papal States between 1282 and 1816. It was established by the War of the Sicilian Vespers (1282–1302), when the island of Sicily revolted and was conquered by the Crown of Aragon, becoming a separate kingdom also called the Kingdom of Sicily. This left the Neapolitan mainland under the possession of Charles of Anjou. Later, two competing lines of the Angevin family competed for the Kingdom of Naples in the late 14th century, which resulted in the death of Joan I by Charles III of Naples. Charles' daughter Joanna II adopted King Alfonso V of Aragon as heir, who would then unite Naples into his Aragonese dominions in 1442.
As part of the Italian Wars, France went to war with Aragon over the kingdom in 1502; the war ended in an Aragonese victory that left Ferdinand II in full control of the kingdom by 1504. The Spanish held control of Naples throughout the 17th century where it remained an important source of economic and military power for the Spanish Crown. After the War of the Spanish Succession in the early 18th century, the possession of the kingdom again changed hands; the 1714 Treaty of Rastatt saw Naples given to Charles VI of the Austrian Habsburgs. However, Naples and Sicily were conquered by Charles, Duke of Parma (of the Spanish Bourbons) during the War of the Polish Succession in 1734, he was then installed as King of Naples and Sicily from 1735. In 1816, Naples formally unified with the island of Sicily to form the Kingdom of the Two Sicilies.
The territory of the Kingdom of Naples corresponded to the current Italian regions of Campania, Calabria, Apulia, Basilicata, Abruzzo, Molise, and also included some areas of today's southern and eastern Lazio.
The term "Kingdom of Naples" is in near-universal use among historians, but it was not used officially by the government.