Soon after founding Cumae in 1000 BC, colonists from Rhodes established a settlement on the western side of Mt Vesuvius. Many centuries later, Phoenician traders from present-day Lebanon and Greeks from Athens were attracted by the beauty of the coast and so expanded the settlement, christening it Neapolis or New City. It thrived as a center of Greek culture and later, under Roman rule, became a favorite of Roman nobles such as Pompey, Caesar and Tiberius. After successive waves of invasion by the Goths and a period of Byzantine rule, Naples became an independent duchy for about 400 years until it was captured by the Normans in 1139. The Normans in turn were replaced by the German Hohenstaufens, who ruled until 1266. Then Charles I of Anjou took control of the Kingdom of Sicily and turned Naples into its de facto capital. The Angevins were succeeded by the Spanish house of Aragón, under whom the city came to prosper.

In 1503 Naples and the Kingdom of Sicily were absorbed by Spain, which sent viceroys to reign as virtual dictators. Despite their harsh rule, Naples flourished artistically and acquired much of its splendor during this period. It continued to flower when the Spanish Bourbons re-established Naples as capital of the Kingdom of the Two Sicilies in 1734. Aside from a Napoleonic interlude from 1806 to 1815, the Bourbons remained until 1860, when they were unseated by Garibaldi and the Kingdom of Italy.

The city was heavily damaged during more than 100 bombing raids in WWII. Marks can still be seen on many monuments. The Allies subsequently presided over a disastrous period of transition from war to peace - many observers have since attributed the initial boom in the city's organized crime, at least in part, to members of the occupying forces. A severe earthquake in 1980 and the dormant, but not extinct, Vesuvius looming to the east remind Neapolitans of their city's vulnerability. A succession of center-left governments has in recent years driven efforts to clean up the city. Churches, museums and monuments that had been off-limits to visitors for decades have been reopened and tourist areas made safer.