The first settlement is defined as Paleapolis in order to distinguish it from a second settlement built during the 5th century BC, called Neapolis, “new city”. The neapolis was erected toward east and along with it, were built monumental walls around the whole settlement to prevent foreign threats’ attacks. Some part of this structure can still be seen in the Cassaro district.
As the Roman Empire was falling apart, Palermo fell under the control of several Germanic tribes. The first were the Vandals in 440 AD under the rule of their king Geiseric. The Vandals had occupied all the Roman provinces in North Africa by 455 establishing themselves as a significant force. They acquired Corsica, Sardinia and Sicily shortly afterwards.
After the Byzantines were betrayed by Admiral Euphemius, who fled to Tunisia and begged the Aghlabid leader Ziyadat Allah to help him, there was a Muslim conquest of Sicily in 831, which took until 904 against fierce resistance. The Emirate of Sicily was established. The Muslims rule within the whole island lasted for about 120 years. Palermo displaced Syracuse as the prime city of Sicily.
After dynastic quarrels however, there was a Christian reconquers in 1072. The family who returned the city to Christianity were called the Hautevilles, including Robert Guiscard and his army. It was under Roger II of Sicily that Norman holdings in Sicily and the southern part of the Italian Peninsula were promoted from the County of Sicily into the Kingdom of Sicily. The kingdom was ruled from Palermo as its capital, with the king’s court held at Palazzo dei Normanni.