Ptolemais in Cyrenaica (Libya)
The town was most probably founded in 7th or 6th century BC by settlers from Barca. Soon it became one of the founding city-states of the Pentapolis Federation. In 331 BC, the union was dissolved after all of its towns surrendered to Alexander the Great. After his death, the area formed part of the Ptolemaic empire. In early 1st century the region was conquered by Rome and became a separate province.
In 365, a major earthquake struck the region and destroyed all of the five major cities of the area (Cyrene with its port Apollonia, Arsinoe, Berenice, Balagrae and Barca). Ptolemais survived the tragedy in relatively good condition, and it was there that the most important authorities were moved. It served the role of a capital of Cyrenaica until 428, when it was destroyed by the Vandals. During the reign of Justinian I the city was rebuilt, but it never regained its powers and was again destroyed by the Arabs in the 7th century.