The Roman army had a complex command structure and various unit types. It consisted of land, sea, and air forces. The land forces included combat units like heavy and light infantry and cavalry, as well as general staff and supply units. The navy was called the Roman navy. The main land combat unit was the legion, composed of cohorts which were made up of centuria. Auxillary units included alae cavalry wings and cohors infantry cohorts. Officers included generals, tribunes, and the praefectus castrorum. Standards and ranks were displayed through items like fasces, vexilla banners, and insignia carried by positions like the aquilifer and signifer.

1. Selected Sites of Jordan
Military Life in East & West
Summer Semester 2013/14
Professor Dr. Thomas M. Weber

2. The Roman Army
Units: The Types of Legions

3. Roman Army
Command Structure

4. The Roman Army
General Army Units
1. Land Army 2. Sea Army - navy 3. Aviation Army – Air Force
1a. Combat Units -Infantry – heavy
-- light
-cavalry – heavy
-- light
-artillery – heavy
-- light
1c. General Staff - Generals and Ordonances
- Corps of Officers
- Signals
1b. Supply Units - pioneers
- scouts
- ambulance
- suppliers

5. The Roman Navy
General Army Units
2. Sea Army - Roman navy

6. The Roman Army
Legionary Army Units
Important terms
Legio (Imperial) - A legion was composed of nine cohorts and one first cohort. The legion's
overall commander was the legatus legionis, assisted by the praefectus castrorum and other
senior officers.
Cohors (Cohortes) - A cohort consisted of 480 men. The most senior ranking centurion of
the six centuria commanded the entire cohort.
First Cohort (Cohors Prima) - The first cohort was a double strength cohort (consisting of
five double-strength centuria) with a size of 800 men (excluding officers). The centurion of
its first centuria, the Primus Pilus, commanded the first cohort and was also the most
senior Centurion in the legion.
Centuria - A centuria consisted of 80 men under the command of a Centurion and
his Optio. Six centuria formed a cohort.
Contubernium - The smallest organized unit of soldiers in the Roman Army. It was composed
of eight legionaries led by a non-commissioned officer called a decanus. Ten contubernia
formed a centuria.
Vexillatio - These were temporary task forces composed of one or multiple centuria deta-
ched from the legion for a specific purpose. Vexillations were under the command of an
officer appointed by the Legatus.

7. The Roman Army
Army Units
The Centuria

8. The Roman Army
Auxilary Army Units
Ala : The ala was composed entirely of cavalry. The name is Latin for wing and
derives from the use of horsemen on the flanks of an army, where they gave
protection to the infantry centre. The alae were normally of a strength of
roughly five hundred (quingenaria), but there were a few of the strength of
roughly a thousand (millaria)
Turma : By the second century the ala quingenaria were arranged into section
of sixteen turmae, whereas the ala millaria were partitioned into twenty
four turmae. So a turma was not necessarily always of the same size.
Commander: praefectus alae

9. The Roman Army
Auxilary Army Units: Cavalry
Ala Parthorum et Araborum (Mainz)

10. Arabs from Amman serving in the Roman army

11. The Roman Army
General Army Units
Arabian Auxiliary Troops in Service of the Roman Army

12. The Roman Army
General Army Units
Auxiliary Cavalry Troops in Service in exerise

13. The Roman Army
Auxilary Army Units: Cavalry
Ala Augusta

14. The Roman Army
Auxilary Army Units: Infantry
Cohors Dalmatorum

15. The Roman Army
Auxilary Army Units: Dromedarii
Palmyra, Museum

16. The Roman Army
Army Units: Early Arab Dromedar Archers

17. The Roman Allies in Bilad al-Sham
The Ghassanids (Beni Ghassan)
http://www.twcenter.net/forums/showthread.php?185336-Lahkmid-Arabs-
amp-Ghassanid-Auxiliaries
Fancy Computer-Game Ghassanid Soldiers
(without any historic and archaeological evidence)

18. The Roman Army
Command Structure

19. The Roman Army
Military Ranks: The Generals
Legatus Militum – Magister Militum per Orientem
Emperor Traian in the Dacian wars with his Generals

20. The Roman Army
Military Ranks: The Generals
Highest Commander
Legatus Militum (or legionis) – Magister Militum per Orientem
Possible Portrait (unsecure!!!) of the Magister
Militum Flavius Belisarius (Belisarios , Βελισάριος
* around 405 AD, † 565 AD

21. The Roman Army
Army Units and military ranks
Second highest commander
Tribunus Militum
High ranked officer on a temporary limited term of
duty, coming from the Roman nobility. 6 Tribuni per
legion with commanding power. Two ranks must be
distinguished by the purple stripes of the underwear
tunics:

22. The Roman Army
Army Units and military ranks
Third highest commander
Praefectus Castrorum
Camp commander without combat command. He supervised the discipline in the camp.
He was responsible for food and other material supply,
especially on the Department of weaponry
(armentaria), the field hospital, the Department of
accounting and registration (tabulinarium), the
Department of custody.

23. The Roman Army
Army Units and military ranks
Primus Pilus, Centurio and Optio

24. The Roman Army
Army Units and military ranks
Official Insignia: The Fasces and the
Licores (Lictor)

25. The Roman Army
Army Units and military ranks
Official Insignia: The Fasces and the
Licores (Lictor)

26. The Roman Army
Army standards and tactical signs
The Eagle (Aquila) and Roman Standard (vexillum)

27. Vexillarius
The Roman Army
Army standarts and tactical signs
Aquilifer
Signifer

28. The Roman Army
Army standart and tactical signs
Legionary standarts: The Vexilla