Nero, Sestertius with countermark "X" of Legio X Gemina.
Obv: Laureate bust right.
Rev: Nero riding horse right, holding spear, DECVRSIO in exergue; S C across fields.

This is a list of Roman legions, including key facts about each legion, primarily focusing on the Principate (early Empire, 27 BC – 284 AD) legions, for which there exists substantial literary, epigraphic and archaeological evidence.

When Augustus became sole ruler in 31 BC, he disbanded about half of the over 50 legions then in existence. The remaining 28 legions became the core of the early Imperial army of the Principate (27 BC – AD 284), most lasting over three centuries. Augustus and his immediate successors transformed legions into permanent units, staffed by entirely career soldiers on standard 25-year terms.

During the Dominate period (near the end of the Empire, 284–476), legions were also professional, but are little understood due to scarcity of evidence compared to the Principate. What is clear is that late legions were radically different in size, structure, and tactical role from their predecessors, despite several retaining early period names. This was the result of the military reforms of Emperors Diocletian and Constantine I, and of further developments during the 4th century.

The legions were identified by Roman numerals, though the spelling sometimes differed from the modern standard. For example, in addition to the spellings "IV", "IX", "XIV", "XVIII" and "XIX", the respective spellings "IIII", "VIIII", "XIIII", "XIIX" and "XVIIII" were commonly used.[1] Legions also bore a cognomen or nickname. While neither a legion's number or cognomen were likely unique enough to identify it, the combination of the two is usually needed to identify a specific legion. For example, both Legio III Cyrenaica and Legio III Gallica were distinct, long-standing legions of the late Republic and Imperial periods. To visually identify legions, they also bore a specific emblem, a symbolic representation of the legion, frequently an animal or mythological figure, which appeared on the vexillum, a small rectangular flag that served as the legion's standard and carried both the emblem and name of the legion.

Late Republican legions

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.[2] There is little evidence of changes in the wealth and social backgrounds of the men who joined before and after the opening of recruitment,[3] the pay remained pitiful.[4] Conscription remained the main method by which Rome mustered troops.[5] The evidence for the abolition of property requirements is very weak,[6][7] and there were no significant changes in population size or demographics that would drive such a reduction.[8][9][10] The bulk of recruits were still landed citizens, who would appear poor to the elites authoring the surviving sources.[5] Again, their pay was not enough to sustain professional career in the military, and soldiers generally did not expect land grants after discharge.[11]

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 Marc Antony.

Early Empire legions

The Roman empire and legions deployed in AD 125, in the time of emperor Hadrian.

Codes for Roman provinces in the table:

AEG Aegyptus (Egypt)
AFR Africa (Tunisia/Western Libya)
AQ Aquitania (South-Western France)
AR Arabia Petraea (Jordan/Negev/Sinai)
BRIT Britannia (England/Wales)
CAP Cappadocia (Central/Eastern Turkey)
DC Dacia (Romania/Serbia)
DLM Dalmatia (Bosnia-Herzegovina/Croatia/Montenegro/Kosovo/Serbia)
GAL Galatia (Central Turkey)
GI Germania Inferior (Netherlands/Rhineland)
GS Germania Superior (Alsace-Lorraine/Rhineland)
HISP Hispania Tarraconensis (Central Spain)
IT Italia (Italy)
JUD Judaea (Israel/Palestine )
MAUR Mauretania (Western Maghreb)
MCD Macedonia (Southern Balkans/Greece)
MI Moesia Inferior (Romania/Bulgaria)
MS Moesia Superior (Serbia)
NR Noricum (Austria)
PAN Pannonia (Hungary/Slovakia/Croatia/Slovenia)
RT Raetia (Switzerland/Germany)
SYR Syria (Syria/Lebanon)
Roman legions of the early Empire (units founded between 59 BC and AD 250)
Legion no.
and title (cognomen)
legionary base
Emblem Date founded/
Castra legionaria (legion bases)[12]
* = main base. Start date 31 BC if unspecified
I Adiutrix Szőny, Hungary Capricorn 68 Nero 444 70–86 Moguntiacum (GS); 86 – mid-5th century Brigetio* (PAN) "1st Rescuer". Was raised from marines of Classis Misenensis
I Germanica Bonn, Germany Bull 48 BC Caesar 70 DD to 16 BC HISP; c. 5 BC – AD 70 Bonna* (GI) Disbanded for cowardice in Batavi revolt
I Italica Svishtov, Bulgaria Boar 66 Nero post 400 70 – early 5th century Novae* (MI) prima Italica:raised for aborted Caucasus war
I Macriana 68 Macer 69 DD (Raised for mutiny against Nero by Macer, gov of AFR) liberatrix: "Liberator 1st". Disbanded by Galba
I Minervia Bonn, Germany Minerva 82 Domitian post 300 82 – 4th century Bonna* (GI) "Minerva-revering 1st"
I Parthica Sinjar, Iraq Centaur 197 S. Severus post 400 197 – early 5th century Nisibis* (SYR) Raised for Severus' Parthian campaign in 197
II Adiutrix Budapest, Hungary Capricorn 70 Vespasian after 269 70–87 BRIT; 87–106 MS; 106 – at least 269 Aquincum* (PAN) "2nd Rescuer." Was raised from marines of Classis Ravennatis
II Augusta Caerleon, Wales Capricorn before 9 BC Augustus after 300 to c. AD 9 HISP; 43–74 BRIT; 74 – at least 255 Isca Augusta* (BRIT) Failed to engage Boudica 60. c. 395 at Rutupiae (BRIT)
II Italica Enns, Austria She-Wolf 165 M Aurelius after 400 180 – c. 400 Lauriacum* (NR) Capitoline Wolf Rome's national emblem
II Parthica Castra Albana, Italy Centaur 197 S. Severus after 312 197–218 Castra Albana (IT); 218–234 Apamea (SYR); 238 – c. 300 Castra Albana(IT) 4th century recorded at Bezabde (SYR)
II Traiana Alexandria, Egypt Hercules 105 Trajan after 400 125 – 5th century Nicopolis* (AEG) secunda fortis "Trajan's valliant 2nd"
III Augusta Batna, Algeria Pegasus 43 BC Augustus after 350 to 20 AFR; 20–75 Ammaedara; 74 – after 350+ Lambaesis* (MAUR) Decimated for cowardice in Mauri war (AD 18)
III Cyrenaica Busra, Syria 36 BC M Antony after 400 to 35 Thebes 35–125 Alexandria AEG; 125 – 5th century Bostra* AR "3rd from Cyrene"
III Gallica Raphanea, Syria Two Bulls 49 BC Caesar after 300 31 BC– 4th century Raphanea* (SYR) tertia Gallica: "3rd from Gaul"
III Italica Regensburg, Germany Stork 165 M Aurelius after 300 165 – 4th century Castra Regina* (RT) Raised for war on Marcomanni
III Parthica Ras al-Ayn, Syria Bull 197 S. Severus after 400 197 – 4th century Resaena* (SYR) Raised for Severus' Parthian campaign in 197
IV Flavia Felix Belgrade, Serbia Lion 70 Vespasian before 400 86 –108 Singidunum* MS, 108-118/9 Bersobis* DC, 118/9-4th century Singidunum* (MS) Vespasian's lucky 4th. Reformed IV Macedon
IV Macedonica Mainz, Germany Bull 48 BC Caesar 70 DD to 43 HISP; 43–70 Moguntiacum* (GS) Disbanded in Batavi revolt
IV Scythica Gaziantep, Turkey Capricorn 42 BC M Antony after 400 to 58 MS; 68 – 5th century Zeugma* (SYR) quarta scythica: "Scythian-conquering 4th"
V Alaudae Xanten, Germany Elephant 52 BC Caesar 70 or 86 XX to 19 BC HISP; c. 10 BC – AD 70 Castra Vetera* (GI) "Larks 5th" Feathers in helmet? XX during Batavian rebellion in 70 or at the first Battle of Tapae in 86
V Macedonica Turda, Romania Eagle 43 BC Augustus after 600 6–101 Oescus, 107–161 Troesmis (MI); 166–274 Potaissa* (DC) quinta macedonica: "5th from Macedonia"
VI Ferrata Galilee, Israel She-Wolf 58 BC Caesar at least 250 UF to 71 Raphana (SYR); 135 – at least 250 Caparcotna* (JUD) "Ironclad 6th". XX at Battle of Edessa 260?
VI Hispana post 212 after 250 UF unknown Only 1 record. XX at Battle of Abrittus 251?
VI Victrix York, England Bull 41 BC Augustus after 400 to 70 Castra Legionis HISP; 71–122 GI; 122 – c. 400 Eburacum* BRIT "Victorious 6th" built Hadrian's Wall 122–132
VII Claudia Kostolac, Serbia Bull 58 BC Caesar c. 400 to AD 9 GAL; 9–58 DLM; 58 – c. 400 Viminacium* (MS) septima Claudia: title for crushing mutiny 42
VII Gemina León, Spain 68 Galba c. 400 75 – c. 400 Castra Legionis* HISP Raised in Hispania by Galba for march on Rome
VIII Augusta Strasbourg, France Bull 59 BC Caesar after 371 9-45 Poetovium; 45–69 Novae MI; 69–86 Mirebeau-sur-Bèze GS; 86 – at least 371 Argentorate* GS octava Augusta:
IX Hispana York, England Bull 41 BC Augustus 132? 161? to 13 BC HISP; AD 9–43 PAN?; 71–121 Eburacum* BRIT; 121–130 Nijmegen GI? nona Hispana: XX in Judaea (132)? XX by Parthians in Armenia (161)
X Fretensis Jerusalem Boar 40 BC Augustus after 400 to 25 BC JUD; 25 BC – AD 66 SYR; 73 – at least c. 400 Hierosolyma* fretum = Strait of Messina, Naulochus 36 BC
X Gemina Vienna, Austria Bull 42 BC Lepidus after 400 30 BC – AD 63 Petavonium HISP; 63–68 Carnuntum PAN; Petavonium 68–71 HISP; 71–103 Noviomagus GI; 103 – c. 400 Vindobona* PAN Was X Equestris, Caesar's "mounted" legion
XI Claudia Silistra, Bulgaria Neptune 42 BC Augustus after 400 to 71 DLM; 71–104 Vindonissa RT; 104 – c. 400 Durostorum* MI undecima Claudia: honoured by Claudius
XII Fulminata Malatya, Turkey Thunderbolt 43 BC Lepidus after 400 to 14 AEG; 14–71 Raphana (SYR); 71 – c. 400 Melitene* (CAP) Thunderbolt 12th lost aquila in 1st Jewish War
XIII Gemina Alba Iulia, Romania Lion 57 BC Caesar after 400 45–106 Poetovio PAN; 106–270 Apulum* DC; 270–400 MI "Twinned 13th". Crossed Rubicon with Caesar 49 BC
XIV Gemina Petronell, Austria Capricorn 57 BC Caesar after 400 AD 9–43 Moguntiacum GS; 43–58 Mancetter BRIT; 58–67 Wroxeter BRIT; 67–89 Balkans; 92–106 Vindobona PAN; 106 – c. 400 Carnuntum* Defeated Boudica's Britons at Watling Street (60)
XV Apollinaris Saddagh, Turkey Apollo 41 BC Augustus after 400 14–62 Carnuntum PAN; 62–73 SYR 71–115 Carnuntum PAN; 115 – c. 400 Satala* CAP "Apollo-revering 15th". Fought in First Jewish War
XV Primigenia Xanten, Germany Fortuna 39 Caligula 70 XX 39–43 Moguntiacum (GS); 43–70 Castra Vetera* (GI) Primigenia goddess of Fate. XX in Batavi revolt
XVI Flavia Firma Samsat, Turkey Lion 70 Vespasian post 300 70–117 Satala (CAP); 117 – at least 300 Samosata* SYR "Vespasian's steadfast 16th". Reformed XVI Gallica
XVI Gallica Mainz, Germany Lion 41 BC Augustus 70 DD to 43 Moguntiacum* (GS); 43–70 Novaesium* (GI) Disbanded for cowardice in Batavi revolt
XVII Xanten, Germany 41 BC Augustus AD 9 XX to 15 BC AQ?; 15 BC – AD 9 Castra Vetera* (GI) Destroyed in Teutoburg Forest, lost aquila standard, never rebuilt
XVIII Xanten, Germany 41 BC Augustus AD 9 XX to 15 BC AQ?; 15 BC – AD 9 Castra Vetera* (GI) Destroyed in Teutoburg Forest, lost aquila standard, never rebuilt.
XIX Xanten, Germany 41 BC Augustus AD 9 XX to 15 BC unknown; 15 BC – AD 9 somewhere in GI Possibly saw action in the conquest of Rhaetia in 15 BC. Destroyed in Teutoburg Forest, lost aquila standard, never rebuilt.
XX Valeria Victrix Chester, England Boar 31 BC Augustus after 250 UF to AD 9 Burnum DLM; 9–43 Oppidum Ubiorum GI; 43–55 Camulodunum* BRIT; 55–66 Burrium* BRIT; 66–78 Viroconium* BRIT; 78–88 Inchtuthil* BRIT; 88 – at least 250 Deva* BRIT vigesima named for Messalla? XX in Allectus' fall 296?
XXI Rapax Vindonissa (Windisch, Switzerland) Capricorn 31 BC Augustus 92 XX AD 9–43 GI; 43–70 Vindonissa* (RT); 70–89 GI; 89–92 PAN "Predator 21st". XX by Roxolani Sarmatian tribe PAN
XXII Deiotariana Alexandria, Egypt 48 BC Deiotarus 132? 161? XX to c. 8 BC GAL; c. 8 BC – at least 123 Alexandria* (AEG) GAL king "Deiotarus's 22nd". XX by Jewish rebels in 132? or by Parthians in Armenia in 161?
XXII Primigenia Mainz, Germany Hercules 39 Caligula after 300 39 – c. 300 Moguntiacum* (GS) Raised for Caligula's German war
XXX Ulpia Victrix Xanten, Germany Jupiter 105 Trajan post 400 105–122 DC; 122 – c. 400 Castra Vetera* (GI) "Trajan's victorious 30th" (M Ulpius Traianus)


Legion number and title (cognomen)

The numbering of the legions is confusing, since several legions shared the same number with others. Augustus numbered the legions he founded himself from I, but also inherited numbers from his predecessors. Each emperor normally numbered the legions he raised himself starting from I. However, even this practice was not consistently followed. For example, Vespasian kept the same numbers as before for legions he raised from disbanded units. Trajan's first legion was numbered XXX because there were 29 other legions in existence at the time it was raised; but the second Trajanic legion was given the sequential number II. XVII, XVIII and XIX, the numbers of the legions annihilated in the Teutoburg Forest, were never used again. (These three legions are without titles, suggesting that in disgrace their titles may have been deliberately forgotten or left unmentioned.) As a result of this somewhat chaotic evolution, the legion's title became necessary to distinguish between legions with the same number.

Legions often carried several titles, awarded after successive campaigns, normally by the ruling emperor e.g. XII Fulminata was also awarded: paterna (fatherly), victrix (victorious), antiqua (venerable), certa constans (reliable, steadfast) and Galliena (Gallienus '). Pia fidelis (loyal and faithful), fidelis constans and others were titles awarded to several legions, sometimes several times to the same legion. Only the most established, commonly used titles are displayed on this table.

The geographical titles indicate

Legions bearing the personal name of an emperor, or of his gens (clan) (e.g. Augusta, Flavia) were either founded by that Emperor or awarded the name as a mark of special favour.

The title GEMINA means that two diminished legions have been combined to make one new one.

Main legionary base

This shows the castra (base) where the legion spent the longest period during the Principate. Legions often shared the same base with other legions. Detachments of legions were often seconded for lengthy periods to other bases and provinces, as operational needs demanded.


Legions often sported more than one emblem at the same time, and occasionally changed them. Legions raised by Caesar mostly carried a bull emblem originally; those of Augustus mostly a Capricorn

Date disbanded

For legions that are documented into the 4th century and beyond, we do not know when or how they were terminated. For legions disappearing from the record before 284, the reason (certain or likely) is given as:

Castra legionaria

Indicates the bases (castra) and/or provinces where the legion was based during its history, with dates.


Contains points of note, including explanation of titles and details of a legion's fate.

Province names and borders are assumed throughout the Principate period as at 107, during the rule of Trajan, and after the annexation of Dacia and Arabia Petraea. The map above shows provinces at the end of Trajan's reign, 117. They are the same as in 107, except that Armenia and Mesopotamia have been annexed (they were abandoned soon after Trajan's death); and Pannonia has been split into two (the split occurred c. 107). In reality provincial borders were modified several times between 30 BC and 284: this explains any discrepancy with other sources, as to a legion's location at a particular date.

Late Empire legions

Main article: Late Roman army

Shield pattern of the palatina legion of the Ioviani seniores, according to the Notitia Dignitatum.

Diocletian reorganized the Roman army, in order to better counter the threat of the Germanic peoples of northern Europe as well as that of the Persians from the East. The army was formed by border and field units.

The border (limitanei) units were to occupy the limes, the structured border fortifications, and were formed by professional soldiers with an inferior training.

The field units were to stay well behind the border, and to move quickly where they were needed, with both offensive and defensive roles. Field units were formed by elite soldiers with high-level training and weapons. They were further divided into:

  1. Scholae: the personal guard of the Emperor, created by Constantine I to replace the Praetorian Guard;
  2. Palatinae: "palace troops" were the highest ranked units, created by Constantine I after he disbanded the Praetorian Guard, it was comprised originally of former guardsmen;
  3. Comitatenses: regular field units, some were newly-formed, others were descended from Early-Empire legions;
  4. Pseudocomitatenses: these were limitanei units diverted into the field army and often kept there; some Early Empire legions became pseudocomitatenses units.

These units usually numbered between 300 and 2,000 soldiers and some of them kept their original numbering schemes. The primary source for the legions of this era is the Notitia Dignitatum, a late 4th-century document containing all the civil and military offices of both halves of the Roman Empire (revised in c. 420 for the Western Empire).

See also


  1. ^ Boyne, William (1968). A manual of Roman coins. p. 13.
  2. ^ Gruen 1995, p. xvii.
  3. ^ Rich 1983, p. 329; Gruen 1995, pp. xvii, 367; Evans 1995, p. 91.
  4. ^ Gruen 1995, p. 369. "Bare subsistence"..
  5. ^ a b Rafferty 2021.
  6. ^ Cadiou 2018, pp. 52–53.
  7. ^ Rosenstein, Nathan S (2004). Rome at war: farms, families and death in the middle republic. Studies in the history of Greece and Rome. Chapell Hill, NC: University of North Carolina Press. pp. 14, 235 n. 75. ISBN 978-0-8078-2839-7. The figures of 11,000, 4,000, and 1,500 asses are reported in the sources; "nothing warrants the presumption that the figures are to be arranged in a descending sequence" however.
  8. ^ Cadiou 2018, pp. 42 n. 24, 49–50.
  9. ^ Cadiou 2018, p. 48 n. 64, also mentioning an alterative theory – given in Shochat 1980, pp. 62–64 – that reductions in property qualifications, if they happened, were driven not by a quantitative shortage of assidui but rather a shortage of assidui willing to serve.
  10. ^ Rich 1983, p. 316. "The view that the property qualification... was progressively reduced derives much of its plausibility from the fact that it fits well with received doctrine on Roman manpower... It would thus smack of circularity to use the supposed second century reduction in the property qualification as evidence for the shortage of assidui."
  11. ^ Gauthier 2015, p. 101; Keaveney 2007, p. 62.
  12. ^ "Roman Legionary Fortresses". Archived from the original on 2016-12-20.
  13. ^ "Legio I Flavia Gallicana Constantia - Livius". Retrieved 2020-08-06.
  14. ^ a b History of the Roman Legions.
  15. ^ a b Lacey, James (2016). Great Strategic Rivalries From the Classical World to the Cold War. Oxford University Press.
  16. ^ a b "Legio I Flavia Martis - Livius". Retrieved 2020-08-06.
  17. ^ "Legio I Iulia Alpina - Livius". Retrieved 2020-08-06.
  18. ^ a b "Legio I Martia - Livius". Retrieved 2020-08-06.
  19. ^ a b "Legio I Pontica - Livius". Retrieved 2020-08-06.
  20. ^ DuBois, Michael (2016). Auxillae. ISBN 978-132-963-758-0.
  21. ^ Lenski, Noel (2006). The Cambridge Companion to the Age of Constantine. Cambridge University Press.


Primary sources

Secondary sources