Cyrenaica, Or Cyrensea, an ancient country of Africa, in the N. E. part of modern Tripoli, bounded N. by the Mediterranean, E. by Mar-marica, S. by the desert, and W. by the Greater Syrtis, now the gulf of Sidra. In its widest limits it included Marmarica on the east, and extended to the Araa Philaenorum on the west, and thus corresponded with modern Barca. The centre is a moderately elevated table land, sloping gradually and in terraces down to the hilly coast land, which, from its position, climate, and soil, is one of the most delightful regions of the earth. It abounds in excellent fruits, vegetables, flowers, and rare plants. Cyrenaica was one of the most flourishing colonies of the Greeks, having been settled by Dorians from the island of Thera. Battus, the leader of the original colony, founded Cyrene in 631 B. C, and a dynasty which numbered four kings of his name and four named Arcesi-laus. Battus IV. was killed about 450, and a republic was established, soon replaced by a new tyranny. When Alexander the Great invaded Egypt, the Cyrenaeans were his allies.
After his death the first of the Ptolemies annexed their country to Egypt, and his successors possessed it till about 96 B. C, when Apion, the last governor, an illegitimate son of Ptolemy Physcon, made it over to the Romans. Under the Ptolemies the country was also known as Pentapolis, from the five principal cities: Cyrene; Apollonia, the port town of the preceding; Ptolemais, on the site of the port of Barca, now Tolmeta; Arsinoe, more anciently Tauchira, now Taukra; and Berenice, more anciently Hesperides, now Benghazi, at the mouth of the Lathon. The Romans, who first proclaimed the freedom of the country, soon annexed it as a province, together with Crete, under the name of Cyrenaica. Under Constantino the Great it became a separate province, and was called Upper Libya. Bloody struggles with the revolted Jewish inhabitants under Trajan, repeated incursions of the nomadic tribes of the interior, earthquakes and locusts, gradually destroyed the wealth of the province; its invasion by the Persians, and soon after by the Saracens, in the 7th century, completed its ruin.
Cyrenaica was the chief seat of the disciples of Aristippus, and in a later period of the African Gnostics. The whole region abounds in remnants of antiquity. - See Delia Cella, Viaggio da Tripoli alle frontieri occidentali dell' Egitto (Genoa, 1819); Pacho, Voyage dans la Marmarique, la Cyrenaique, etc. (Paris, 1825-'9); Beechey, " Proceedings of the Expedition to Explore the Northern Coast of Africa" (London, 1828); Trighe, Res Cyrenensium (Copenhagen, 1828); Hamilton, "Wanderings in North Africa;" and Rawlin-son's notes to Herodotus, book iv.