CYRENAICA, or PENTAPOLIS, in ancient geography, a district of Africa, on the shores of the Mediterranean Sea, lying exactly opposite to Greece, at the distance of about 250 miles. It received the name of Cyrenaica from Cyrene, its chief city ;.and that of Pentapolis from the fact of its containing five principal cities, Berenice or Hesperus, Barce, Cyrene, Apollonia, and Arsina or Teucheira, now identified respectively with Benghazi, El Merdj, Grennah or Shahat, Marsoe, Sousah, and Tocra. The district extended inland about 80 miles, and included that portion of the African continent which stretched from the frontier of Egypt on the east to the borders of Africa Propria on the west which were marked by the tumuli of Arm Philaeforum. On its southern frontier Cyrenaica is protected from the scorching winds of the Sahara by a range of lofty mountains which descend in gradual slopes to the sea, and produce within a small compass a great variety of climate and temperature. Its vegetable products consequently comprised all the more important. species to be found in the tropical and temperate zones ; and, as its position was admirably adapted for commerce, nothing was wanting but an enter-prizing population to make it one of the most valuable countries in the world. The people of Thera, under Battus, a native of that island, were the first to colonize Cyrenaica. After a slight opposition from the native tribes, they established themselves in the country, and founded Cyrene in 631 B.C. There soon sprang up in advantageous situations other cities which, while acknowledging Cyrene as the capital of the country, were really independent, and at length threw off its yoke altogether. After the invasion of Cambyses the regal form of goveinment was entirely abolished, and the republican substituted in its room. Under the Ptolemaic dynasty of Egypt (with which country Cyrenaica was incorporated in 321 B. C.), Cyrenaica rose into great importance from the extent and value of its commerce. In 06 B.C. it was bequeathed by will to the Romans by Apion, the last lineal representative of the Ptolemies. Soon afterwards, but at what date is not absolutely fixed, it became a Roman province, and along with the island of Crete was governed by a Roman proconsul. The commercial prosperity of Cyrenaica, however, continued unimpaired till the revolt of the Jews in the province during the reign of Trojan. This revolt was quelled only after the most bloody atrocities had been perpetrated on both sides ; and the population was so much diminished in the contest, that the native tribes recommenced their incursions, and overran the province up to the walls of the principal cities. In the middle of the 7th century the whole country passed into the hands of the Saracens. From that time till the present the country has been occupied by tribes of wandering Arabs, nominally subject to the pasha of Tripoli.

See Thrige, Historia Crease, 1819 ; in which all the passages of the ancient writers about Cyrene are brought together ; Gottschick, Geschickte der Griindung and Mate des Mellen. Steals in Cyrene, 1858; Falbe and Lindberg's Numismatique de l'Ancicnne elfrigue ; and Grote's history of Greece, vol. iv.