Ptolemais or Ptolemaida (Greek: Πτολεμαίς) was one of the ancient capitals of Cyrenaica. It was probably named after Ptolemy III Euergetes. Its Latin name in Roman times was Tolmeta, from which the modern Libyan town of Tolmeitha (Arabic طلميثة) derives its name.
The town was most probably founded in 7th or 6th century BC by settlers from Barka. Soon it became one of the founding city-states of the Pentapolis federation. In 331 BC the union was dissolved after all of its towns surrendered to Alexander the Great. After his death the area formed part of the Ptolemaic empire. In early 1st century the region was conquered by Rome and became a separate province. Roman Tolmeta had no local water supply, but Roman architects built a conduit from the hills and stored the water in eighteen huge galleries under the forum, about fourteen feet high by ten feet wide. These are in perfect repair and were rediscovered during the Italian occupation. In the course of military operations against rebels, it was discovered that the rebels used the underground as a place of hiding; two or three hundred men could easily be hidden in them.
In 365 a major earthquake struck the region and destroyed all of the five major cities of the area (Cyrene with its port Apollonia, Arsinoe, Berenice, Balagrae and Barca). Ptolemais survived the tragedy in relatively good condition, and it was there that the most important authorities were moved. It served the role of a capital of Cyrenaica until 428, when it was destroyed by the Vandals. During the reign of Justinian I the city was rebuilt, but it never regained its powers and was again destroyed by the Arabs in the 7th century.
Buried in the sands, the town's ruins have been remarkably well preserved. West of the city stands a conspicuous and tower-like Hellenistic mausoleum, and there is also a Greek theatre cut into the hillside behind the city. It is probably the only well-preserved Roman capital of a province in the world. In 2001 the archaeological mission from the Warsaw University started the excavations there. It is estimated that the town covers 2.5 square kilometres, excluding the city walls and large necropolis surrounding it.
In May 2011, a number of objects excavated from Ptolemais in 1937 and held in the vault of the National Commercial Bank in Benghazi were stolen. Looters tunnelled into the vault and broke into two safes that held the artefacts which were part of the so-called 'Benghazi Treasure' . The whereabouts of these objects are currently unknown.
See also 
|Wikimedia Commons has media related to: Ptolemais|
- Ptolemais - home page (Polish, English)
- Excavations - preliminary reports
- Ptolemais survey, Libya (nondestructive archaeology)
- Ptolemais City