| Legio III Augusta | |
|---|---|
 Map of the Roman empire in CE 125, under emperor Hadrian, showing the Legio III Augusta, stationed at Lambaesis (Batna, Algeria), in Africa Proconsularis province, from CE 75 until the 4th century | |
| Country | Roman Republic and Roman Empire |
| Type | Roman legion (Marian) |
| Role | Infantry assault |
| Size | 5000–6000 |
| Garrison/HQ | Lambaesis (128 – early 4th century) |
| Engagements |
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| Commanders | |
| Notable commanders | |
Legio III Augusta ("Third Augustan Legion") was a legion of the Imperial Roman army. Its origin may have been the Republican 3rd Legion which served the general Pompey during his civil war against Gaius Julius Caesar (49–45 BC). It supported the general Octavian (later emperor Augustus) in his civil war against Mark Antony (31–30 BC). It was officially refounded in 30 BC, when Octavian achieved sole mastery of the Roman empire. In that year, it was deployed in the Roman province of Africa, where it remained until at least the late 4th century AD.