Not knowing quite where Libya was, the Theran elders searched far and wide for a guide, finally finding a cloth merchant who offered to lead them to the island of Platea off the Libyan coast. After reconnoitering the island, the advance party returned to Thera where the elders drafted colonists by lots and put them under the command of Battus and equipped them with two penteconters. Not long after setting out, the would-be colonists attempted to return to Thera, but were driven off with showers of missiles. They eventually settled on Platea, but the drought continued in Thera and another oracle chided the Therans for not establishing their settlement on the mainland of Libya. This they finally did, convincing Battus and the Therans on Platea to shift the colony to Aziris on the Libyan mainland, where they struggled for six years. Finally, the native Libyans led the Theran colonists to the west, across the rich district of Irasa in the dead of night, to a high plateau on the upper slopes of Jabal Al-Akhdar, overlooking the sea. Here there was a spring, dedicated to Apollo, which was named Cyre (Kyre).
During the reigns of Battus (40 years) and his son Arcesilaus (16 years), the colony struggled. During the rein of the third king, Battus the Happy, however, the oracle at Delphi encouraged the migration of Greeks to Cyrene, and a multitude of new settlers expanded outward to form new settlements, seizing lands from the neighboring Libyans. The port city of Barca (Barke) was founded at this time. The Libyan king Adicran appealed to Egypt for aid, prompting the Pharoah Apries to lead a large army against Cyrene, blissfully ignorant of the military prowess of Greek hoplites. The Cyrenaeans soundly defeated Apries, and his defeat prompted an Egyptian revolt in 570 BC. The Achaemenids conquered Egypt in 525 BC, ending Egyptian attempts at hegemony, while showing only modest interest in Cyrene itself, allowing the Battiad Dynasty to rule as satraps.
In subsequent years, Cyrene and its port at Apollonia (Marsa Sousa) became the chief town of the Lybian region between Egypt and Carthage, and traded with all the major Greek cities, reaching the height of its prosperity in the 5th century BC. Greek colonists continued to overflow the city, creating new cities and ports, which operated within the Cyrenean sphere. The region was fertile and well-watered, with hills and light woods, in sharp contrast to the balance of Libya.
In 431 BC, Arkesilas IV was assassinated, ending the Battiad Dynasty. Cyrene became a republic following a civil war with Thibron in which the Cyrenean republicans mustered an army of 30,000, including Carthaginian and Libyan allies.
According to Thucydides (7.59), Spartan reinforcements (comprised of helots and ex-helots) bound for Sicily was blown off course to Libya in 414/413 BC. They were given two trieres by Cyrene, and repaid the favor by joining with Euesperides against the Libyans. a allied with Euesperides against the Libyans.
The city made alliance and was subsequently absorbed into Alexander's Macedonian empire. In 324 BC, a rogue band of 5000 mercenaries under the command of Harpalus (who as later assassinated) and the Spartan captain Thibron took refuge in Crete, where a number of Cyrenean exiles persuaded them to reestablish themselves in Cyrenaicia. The pirate army landed first at Cyrene, seizing the nearby harbor and defeating the Cyrene army outside their gates. Beseiged, the city fathers paid a ransom of 500 talents of gold and chariots, and Thibron's pirates moved out to prey on other Cyrenaician cities. Feuded by local rivalies, the cities of Barca and Hesperis supported Thibron, who also recruited mercenaries from the Peloponnese. Cyrene raised its own army of 30,000 with Carthaginian and Libyan allies. A great battle ensued, with the Cyrenaician army proving no match for Thibron's experienced veterans. Cyrene was beseiged, and at the height of the seige, a republican coup within the city prompted the oligarchs and upper class to flee, many taking refuge with Thibron and others trekking to Egypt to plead for Ptolemaic intervention. Ptolemy sent an army under Ophellas, which prompted erstwhile foes Thibron and Cyrene into a futile alliance. Ophellas easily overwhelmed the allied force, capturing and crucifying the Spartan adventurer Thibron.
Ophellas was appointed Ptolemy's governor or satrap (c. 322 BC) but revolted in 312 BC, ruling thereafter as an independent leader, thus representing the start of the Cyrenean I/56b list. Ophellas took an Cyrenean army with Athenian allies to support Agathokles of Syracuse against the Carthaginians in the first Punic War, but was murdered for his troubles in 308 BC. Again Cyrenea resisted attempts to restore Ptolemaic rule, but after five years Ptolemy's half-brother Magas (son of Berenice) was able to capture Cyrene and establish himself as governor.
After a time, Magas fashioned himself as king of Cyrene (283/277 BC) and planned an invasion of Egypt. Ptolemy hired mercenaries and garrisoned the frontier in anticipation of their advance, but the Cyrene army was forced to turn back to deal with the revolt of the Marmaridae, a tribe of Libyan nomads. His military plans thwarted, Magas turned to political intrique. Using his marriage ties to Apame, daughter of Antiochus, Magas persuaded Antiochus to break the treaty which his father Seleucus had made with Ptolemy and to attack Egypt. Although Antiochus' plans failed to come to fruition, the threat distracted Ptolemy's attention from Cyrene. Magas ruled until his death in 250 BC, whereupon the Cyrenaica formed a loose federal government aided by Demophanes and Ekdemus of Arcada.
In 246 AD, Berenike II, the daughter of Magas, married Ptolemy III, and Cyrenaica was reunited with Egypt. During the subsequent period of loose Ptolemaic rule, the Cyrenaican cities continued to grow and were equipped with permanent defensive walls. The old port of Barca was greatly expanded and renamed Ptolemais. Euesperides (Beaghazi) was renamed Berenice, and Taucheira (Tocra) became Arsinoe. Cyrene's port at Apollonia was recognized as an independent city, and the region of Cyrenaica became known as the Pentapolis or the land of the five cities.
According to Polybios, the Cyreneans revolted against Ptolemy Physkon in 163 BC. In a pitched battle, Physkon drove off the Cyreneans Libyan allies but was unable to crack the Cyrenean phalanx. Cyrenaicia remained an independent kingdom under Ptolemy VIII until reabsorbed in 146 AD.
In 96 B.C. the region of Cyrenaica was willed by Ptolemy Apion to Rome as an independent kingdom. The quaestor Cornelius Lentulus Marcellinus arrived in 74 BC and officially annexed the region as a Roman province, thus ending this army list. The city of Cyrene thrived under Roman rule until factions within the city rebelled during the Jewish revolt of 115 AD. The heavy-handed Roman General Marcus Turbo suppressed the rebellion by killing over 20,000 civilians and destroying much of the city, which never fully recovered.