Republican legions were formed by compulsory levy of Roman citizens (who met a minimum property qualification) and raised whenever it was necessary. Usually they were authorized by the
Roman Senate and later disbanded. Throughout the late Republic, soldiers and commanders served only for short periods intending, respectively, to secure plunder or political advancement from military victory. There is little evidence of changes in the wealth and social backgrounds of the men who joined before and after the opening of recruitment; the pay remained pitiful. Conscription remained the main method by which Rome mustered troops. The evidence for the abolition of property requirements is very weak, and there were no significant changes in population size or demographics that would drive such a reduction. The bulk of recruits were still landed citizens, who would appear poor to the elites authoring the surviving sources. Again, their pay was not enough to sustain professional career in the military, and soldiers generally did not expect land grants after discharge. In the last century of the Republic,
proconsuls governing frontier provinces became increasingly powerful. Their command of standing legions in distant and arduous military campaigns resulted in the allegiance of those units transferring from the Roman state to themselves. These
imperatores (lit: victorious generals, from the title
imperator they were hailed with by their troops) frequently fell out with each other and started civil wars to seize control of the state, such as
Sulla,
Caesar,
Pompey,
Crassus,
Mark Antony and Octavian (later
Augustus, the first Emperor himself). In this context, the
imperatores raised many legions that were not authorised by the Senate, sometimes having to use their own resources. As civil wars were resolved, many of these "private" units would be disbanded, only for more to be raised to fight the next civil war. By the time Augustus emerged as sole ruler of Rome in 31 BC, over 50 legions were in existence, many of which were disbanded. The legions included in the following list had a long enough history to be somehow remarkable. Most of them were levied by Julius Caesar and later included into
Octavian's army, some of them were levied by Mark Antony. •
Fimbrian legions: 86 BC – 66 BC,
Lucius Valerius Flaccus. These two legions fought in the
Mithridatic Wars. •
Legio I Germanica (
Germanic): 48 BC – AD 70 (
Revolt of the Batavi),
Julius Caesar (emblem:
bull) •
Legio II Sabina (
Sabine): 43 BC – 4th century AD, early name of the
Legio II Augusta,
Octavian •
Legio III Cyrenaica (
from Cyrene): probably to (at least) the 5th century,
Mark Antony •
Legio III Gallica (
Gallic): around 49 BC to at least early 4th century, Julius Caesar (emblem:
bull) •
Legio IV Macedonica (
Macedonian): 48 BC – AD 70 (renamed by
Vespasian), Julius Caesar (emblem:
bull,
capricorn) •
Legio IV Scythica (
from Scythia): to at least early 5th century, Mark Antony (emblem:
capricorn) •
Legio V Macedonica (
Macedonian): 43 BC – AD 637, Octavian (emblem:
bull) •
Legio V Alaudae (
Larks): 52 BC – AD 70 or 86 (destroyed either during the
Batavian rebellion or by the Dacians in
first Battle of Tapae), Julius Caesar (emblem:
elephant) •
Legio VI Ferrata (
Ironclad): 52 BC – after AD 250, Julius Caesar (emblem:
bull,
she-wolf and
Romulus and Remus); twin legion of
Legio VI Victrix •
Legio VI Victrix (
Victorious): 41 BC – after AD 402, Octavian (emblem:
bull) •
Legio VII Claudia Pia Fidelis (
loyal and faithful to Claudius): 51 BC – 44 BC, Julius Caesar; disbanded and re-formed by Octavian •
Legio VIII Augusta: 59 BC – 46 BC, Julius Caesar, originally named
Gallica, disbanded and re-enlisted by Octavian as
Legio VIII Augusta, 44 BC – AD 420 •
Legio IX Hispana (
Hispanian): before 58 BC – at least AD 120 •
Legio X Equestris (
Equestrian): before 58 BC – 45 BC, Julius Caesar's personal legion, later renamed as
Legio X Gemina •
Legio X Fretensis (
of the sea strait): levied by Octavian in 41/40 BC, recorded to have existed at least until the 410s •
Legio XI Claudia: 58 BC – 45 BC, Julius Caesar (emblem:
Neptune), disbanded, reconstituted by Octavian •
Legio XII Fulminata (
Thunderbolt): 57 BC – AD 45, Julius Caesar, first reconstituted by
Lepidus in 43 BC, named by Mark Antony as Legio XII
Antiqua (
Ancient) •
Legio XIII Gemina (
Twin): 57 BC – 45 BC: Julius Caesar, later (41 BC) reconstituted by Octavian. The legion that crossed the Rubicon with Caesar on his assault on Rome. •
Legio XIV Gemina Martia Victrix (
Twin martial and victorious): 57 BC – 48 BC: Julius Caesar, destroyed and reconstituted in 53 BC. Reconstituted by Octavian after 41 BC. •
Legio XV Apollinaris (''Apollo's'') 41 BC – 40 BC, Octavian, raised to end the occupation of
Sicily by
Sextus Pompeius. •
Legio XVI Gallica (
Gallic) 41 BC – 40 BC, Octavian, disbanded after
Batavian revolt in AD 70. •
Legio XVII raised by Octavian in 41 BC, destroyed in
Teutoburg forest in AD 9 with XVIII and XIX legions. •
Legio XVIII raised by Octavian in 41 BC, destroyed in
Teutoburg forest in AD 9 with XVII and XIX legions •
Legio XIX raised by Octavian in 41 BC, destroyed in
Teutoburg forest in AD 9 with XVII and XVIII legions •
Legio XX Valeria Victrix (
Victorious Valeria) raised by Octavian in 31 BC. •
Legio XX Siciliana: 36 BC – 6 BC, Octavian probably for his campaign against
Sextus Pompey. •
Legio XXI Rapax (
Predator) raised by Octavian in 31 BC • : 49 BC – 42 BC, Julius Caesar • : 49 BC – 30 BC, Julius Caesar • : 49 BC – 30 BC, Julius Caesar • : 47 BC – 31 BC, Julius Caesar • : 49 BC – 30 BC, Julius Caesar • (
Naval): 48 BC – 41 BC, Julius Caesar ==Early Empire legions==