Tripolitania, an ancient region in North Africa bordering the Mediterranean Sea. It forms the coastal strip of the present division of Tripolitania in Libya. In the seventh century B.C. the Phoenicians established three trading posts along the coast and the region became known as Tripolis (Greek for “three cities”). When the Romans defeated Carthage and conquered the whole area in the second century B.C., they colonized the three communities—Sabratha, Oea (now Tripoli), and Leptis Magna (now Homs).
The region was occupied by the Vandals in the fifth century A.D., annexed by the Byzantine Empire in the sixth, and conquered by the Moslems in the seventh. As part of the Barbary States, Tripolitania was a stronghold of corsairs from the 17th to the early 19th century. In 1835–36 Tripolitania became part of the Ottoman Empire.