Ala Arminiana C R Torquata Flavia Firma
This unit is epigraphically attested between the early first and the mid-third centuries AD, beginning its service in Germania Superior. Its recruitment date is not known exactly, but it is not thought to predate to the Augustan age. Some scholars believe its name refers to the Cheruscan nobleman Arminius mentioned by Tacitus (Ann. IV 3; V 31) and Aurelius Victor (XIII, 4), but in the absence of decisive evidence the question must remain open. If it was indeed recruited by that Arminius, it can not much predate the rebellion of Segestes (9-12 AD).
Early epigraphic evidence (CIL XIII 2415 and 12132) indicates that the unit was based in the Haltern area and later moved into permanent quarters at Sediburga near Colonia Augusta Chaucorum. It is here that a body of first-century funerary monuments attest to the continued presence of the force and allow us a glimpse into its makeup. We have the names of four troopers (C. Caelius Cnavo, I. Gu...erus Flavus, Marcus Aulatus, C. Vettius Carobaudes), one subordinate officer (T. Flavius Cautes Vetta dup(larius)) and two centurions (M. Clodius Velleius, T. Fl(avius) Serapion). The prevalence of Germanic names (Cnavo, Carobaudes, Vetta and probably Gu...erus) makes it unlikely that this unit was recruited from among Roman citizens and therefore indicates that its designation as C(ivium) R(omanorum) was won in battle, as was the honorific Torquata. The designators 'Civium Romanorum' and 'Torquata' are absent from the earliest inscriptions and only occur together on CIL XIII 4518, the funerary monument to T. Flavius Serapion found near Seitberg. This stone is dated from internal evidence to between AD 69 and 87, indicating the titles may have been won in the course of the civil war that brought the Flavian dynasty to power. Mommsen believes T. Flavius Serapion to be a promoted soldier of Vespasian's army sent to command a unit of doubtful loyalty, which would make this explanation unlikely.
No inscriptions attesting the Ala Arminiana in the Germanies can confidently be dated after 90 AD, though two are undatable. The first clearly datable evidence for the unit in Pannonia is in 124 AD (CIL III 1276, an incomplete laterculum of the duplarii of the Ala). It is believed to have been transferred in the course of the Dacian Wars and stationed at Ruppiae. The laterculum is also the first inscription to include the title 'Flavia Firma' believed to date to the reign of Domitian. Nine more inscriptions (two tile stamps, an ostracon, two altars and four funerary stones) dating to between AD 126 and the late Severan dynasty were excavated in the area. Naming patterns suggest an influx of local recruits.
The further history of the Ala is shrouded in uncertainty. We know that its camp remained in use until the fifth century (architectural remains suggest a complete remodelling after c. 300), but no epigraphic evidence sheds light on its inhabitants. A doubtful emendation of the Notitia Dignitatum identifies the 'Equ(ites) Armin(iani)' under the command of the Dux of Pannonia Prima (von Seeck prefers 'Equ(ites) Armig(eri)').