Piazza Vittoria (“Victory’s Square”) notable palaces and mosaics have been discovered and a large theatre still existed in the Norman age. According to geographer Strabo, during the Roman Empire it provided large amounts of wheat for the capital. However, after the reign of Vespasian, it decayed, and in 445 was sacked by the King of Vandal Africa, Gaiseric. Later it was part of the territory of Odoacer and Theoderic's Ostrogoths. In 535, the Byzantine general Belisarius stormed the port, during Justinian I's program of reconquering Italy, which soon turned into the fierce and disastrous Gothic War. The Byzantine rule lasted until 831, when the Aghlabid Arabs, disembarked in Mazara del Vallo. The Arabs captured Palermo after a year-long siege and made it the capital city of their Sicilian emirate. Palermo under Arab rule After the Byzantines were betrayed by admiral Euphemius who fled to Tunisia in 827 and begged the Aghlabid leader Ziyadat Allah to help him there was a Muslim conquest of Sicily, putting in place the Emirate of Sicily. The Aghlabids were good administrators. Under their rule Sicily became a rich and flourishing land. The Arab rulers allowed the natives freedom of religion on the condition that they paid a tax. Although their rule was short in time, it was then that Palermo (called Balharm in Arabic) displaced Syracuse as the prime city of Sicily; it was said to have competed with Córdoba and Cairo in terms of importance and splendor. In general, the Arab rule was tolerant, and Jews also had their space and were allowed to prosper. The Arabs are also said to have left a lasting influence on Sicilian culture and especially "the Arab concept of the family", After dynasty related quarrels however, there was a Christian reconquest in the form of the Normans from the Duchy of Normandy, descendants of the Vikings; the family who returned the city to Christianity were called the Hautevilles . Palermo was conquered in 831 by Arabs from North Africa and became the capital of the Arabian Emirate of Sicily until 1072, when it returned under Christian rule due largely to the efforts of Robert Guiscard and his army. For more than two hundred years Palermo was the capital of a flourishing Islamic civilisation in Sicily. The population of the city during this period is uncertain, as figures given by Arab writers during the era were unreliable. Paul Bairoch