Ptolemais was one of the five cities that formed the Pentapolis of Cyrenaica, the others being Cyrene, Euesperides, Tauchira/Teuchira, and Apollonia.

Cyrenaica or Kyrenaika, is the eastern region of Libya. Cyrenaica includes all of the eastern part of Libya between the 16th and 25th meridians east, including the Kufra District. The coastal region, also known as Pentapolis in antiquity, was part of the Roman province of Crete and Cyrenaica, later divided into Libya Pentapolis and Libya Sicca. During the Islamic period, the area came to be known as Barqa, after the city of Barca.