Ancient coastal city, Cyrenaica .
Located in modern Libya, it received its name in the 3rd century BC from Ptolemy III, who united Cyrenaica with Egypt. Its economy was based on trade with the interior, and it flourished in Hellenistic times, in the early period of the Roman Empire, and again from the late 3rd century AD, when Diocletian made it the metropolis of the Roman province of Upper Libya.