Legio XXII Deiotariana Roman Vexillum

The legion XXII Deiotariana originated in the 1st century BC from the army of the Galatian king Deiotarus, ruler of Galatia and a loyal ally of Rome in the wars against Mithridates of Pontus. Trained and organized according to the Roman model, after Augustus annexed Galatia, it was permanently integrated into the imperial army with the number XXII and the cognomen recalling its founder.

Soon after, it was transferred to Egypt, where its main camp was in Alexandria. There, it shared the castrum with Legio III Cyrenaica and ensured control over a strategic province for the Empire's grain supply. In addition to military duties, the legionaries participated in infrastructural projects, from exploiting the quarries of Mons Claudianus to constructing buildings and guarding caravan routes in the desert.

The XXII Deiotariana is attested in action during the Eastern campaigns, the First Jewish–Roman War, and in preparations for the Parthian Wars, distinguishing itself through discipline and reliability. Its last certain mention dates back to the early 2nd century AD; it subsequently disappears from imperial records, likely annihilated or disbanded after the harsh operations during the Bar Kokhba revolt in Judea.