Tigris Boatmen

[Flavius Inismeus]

Hi all,

First of all as always apologies if this question has been answered elsewhere.

As I understand it the legions were the heavy infantry and they used auxiliaries to fulfill certain requirements. I have heard of a unit of the Tigris boatman been stationed at the South Shields section of Hadrians Wall, I would imagine they would move between the banks of the Tyne. My question is does anyone know anything about these Tigris boatmen?

Name: Numeri Bacariorum Tigrisenisium
Raised: Arabia (Tigris).
This base: Arbeia, South Shields, 4th Century AD.
Characteristic: Cohort.
Type: Foot.
Unit size: 200-500
Notes: Name translates to “Tigris small boat men”, maybe it was a Classis, naval unit?
“Arbeia” probably name given to fort after this units origins.
This unit rebuilt the fort after fires in late 3rd and early 4th Century.
Ref: Auxillae, A compendium of Non-Legionary units of the Roman Army, Volume I: Cohortes peditatae and Equitata, Michael S. Dubois.

Self-published work by DuBois is extremely unreliable, I'm afraid. Why is this numerus (not numeri - it's the genitive case in the original, here it looks like it's plural) classified as an infantry cohort? I think no coast of Tigris ever was a part of Roman Arabia.

Deriving "Arbeia" from "Arab" seems possible, but this name is the subject of a multiyear heated discussion - https://archaeologydataservice.ac.uk/lib...pe=Journal ; http://onomastics.ru/en/content/2017-t-14-%E2%84%961-0 etc.