List of Roman Legions - Late Empire Legions

Late Empire Legions

Diocletian reorganized the Roman army, in order to better handle the menace of the barbarians from north 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 2000 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 ca. 420 for the Western Empire).

• Legio I
  • I Flavia Constantia (reliable Flavian): comitatensis unit under the command of the Magister militum per Orientis
  • I Flavia Gallicana Constantia (reliable Flavian legion from Gallia): pseudocomitatensis under the command of the Magister Peditum per Gallias
  • I Flavia Martis (Flavian legion devoted to Mars): pseudocomitatensis
  • I Flavia Pacis (Flavian legion of peace): comitatensis under the command of the Magister Peditum
  • I Flavia Theodosiana: comitatensis
  • I Illyricorum (of the Illyrians): stationed at the Camp of Diocletian in Palmyra
  • I Iovia (devoted to Jupiter): levied by Diocletian, stationed in Scythia Minor
  • I Isaura Sagittaria (archers from Isauria): pseudocomitatensis under the command of the Magister militum per Orientis
  • I Iulia Alpina: pseudocomitatensis under the command of the Magister Peditum in Italy
  • I Martia possibly based near modern Kaiseraugst
  • I Maximiana Thaebanorum (the Thebans of Maximianus): comitatensis unit stationed near Thebes, Egypt, and probably fighting in the battle of Adrianople
  • I Noricorum (of the Noricans): stationed in Noricum
  • I Pontica

• Legio II
  • II Britannica: comitatensis under Magister Peditum
  • II Flavia Constantia: comitatensis under the command of the Magister Peditum
  • II Flavia Virtutis: comitatensis under the command of the Magister Peditum
  • II Herculia (devoted to Hercules): levied by Diocletian, stationed in Scythia Minor
  • II Isaura
  • II Iulia Alpina: pseudocomitatensis under the command of the Magister Peditum, in Comes Illyricum command
  • II Felix Valentis Thebaeorum: comitatensis

• Legio III
  • III Diocletiana
  • III Flavia Salutis: comitatensis under the command of the Magister Peditum
  • III Herculea: comitatensis under the command of the Comes Illyricum
  • III Isaura
  • III Iulia Alpina: comitatensis under the command of the Magister Peditum command in Italy

• Legio IV
  • IV Italica
  • IV Martia
  • IV Parthica

• Legio V
  • V Iovia (maybe the Jovians)
  • V Parthica

• Legio VI
  • VI Gemella
  • VI Gallicana
  • VI Herculia (maybe the Herculians)
  • VI Hispana
  • VI Parthica

• Legio XII
  • XII Victrix