The ancient Greeks founded several colonies on its coast and developed several major cities. The most important foundation was that of Cyrene in 631 BCE by colonists from the island Thera, who had left the island because of a famine. Their commander Aristoteles took the Libyan name Battos. His dynasty, the Battaid, maintained itself in spite of heavy resistance by the Greeks in neighbouring cities.
The east of the province was called Marmarica (no major city), but the important part was in the west, comprising five cities, hence known as the Pentapolis: Cyrene (near the modern village of Shahat) with its port of Apollonia (Marsa Susa), Arsinoe or Taucheira (Tocra), Euesperides or Bernice (near modern Benghazi), Balagrae (Al Bayda) and Barce (Al Marj) – of which the chief was the eponymous Cyrene. The term "Pentapolis" continued to be used as a synonym for Cyrenaica. In the south the Pentapolis faded into the Saharan tribal areas, including the pharaonic oracle of Ammonium.
In 525 BCE, after taking Egypt, the Persians took the Pentapolis. They were followed by Alexander the Great in 332 BCE, who received tribute from these cities after he took Egypt. The Pentapolis was formally annexed by Ptolemy I Soter and it passed to the diadoch dynasty of the Lagids, better known as the Ptolemaic dynasty. It briefly gained independence under Magas of Cyrene, stepson of Ptolemy I, but was reabsorbed into the Ptolemaic empire after his death. It was separated from the main kingdom by Ptolemy VIII and given to his son Ptolemy Apion, who, dying without heirs in 96 BCE, bequeathed it to the Roman Republic, which gave it its current name, Cyrenaica.
With the partitioning of the Roman Empire in 395, Cyrenaica became part of the Eastern Empire.It remained in the power of the Byzantine until the year 641, when the Arabs invaded it.For ten centuries it remained under the rule of different Arab and Berber dynasties.
At the beginning of the XVIIIth century, it turned into a possession of the Ottoman Empire, known as Bengasi. In September, 1911, after the Italo-Turkish War exploded between Italy and the Ottoman Empire, Cyrenaica was occupied by the Italians. At the end of the war, in October 1912, Turkey transferred Cirenaica and Tripoli (which was re-baptized as Tripolitania) to Italy. In 1926, after the Italian defeat in the World war I, Cyrenaica became a independent state.