Legio III Cyrenaica, meaning from Cyrenaica a Roman province, was a Roman legion probably levied by Marcus Antonius around 36 BC, then governor of Cyrenaica. There are still records of the legion in Bostra in the beginning of the 5th century AD. The legion symbol is unknown.
The first historical appearance of the legion is during the campaign of Emperor Augustus Caesar to conquer Egypt in 30 BC. III Cyrenaica would remain in Egypy and, in 35 AD was in Alexandria, sharing camp with Legio XXII Deotariana. The main task of both legions was keep the province safe and to maintain peace and order between the different ethnic and religious groups present in Alexandria.
In the internal turmoils of the Roman Empire, III Cyrenaica tended to follow defeated candidates to the throne like Avidius Crassus (vs. Marcus Aurelius in 175) and Pescinnius Niger (vs. Septimius Severus in 192)
The legion, or subunits of it, probably participated in the following campaigns:
- 25 BC – against Arabia Felix, modern Yemen
- 63 AD – against the Parthian Empire
- 66/70 and 132/136– retaliations on the Jewish rebellions
- 162/166 – against the Parthian Empire, commanded by Lucius Verus
- 215/217 – against the Parthian Empire, commanded by Caracalla