MORE ON THE ALA PETRIANA OF THE STANWIX ROMAN FORT

Staffordshire Moorlands Patera Showing Uxellodunum

on the Right Side Below the Rim

From Professor Anthony Birley on the Ala Petriana at Stanwix:

That the praef. alae Petrianae at Stanwix was the "senior officer" of the Wall garrison is simply a statement of fact: he was the only prefect of an ala milliaria in the entire province and thus was in the quarta militia, the elite highest grade for equestrian officers, probably only created in the early 2nd century. For the regiment see e.g. M.G. Jarrett in the journal Britannia for 1994. Whether this officer ex officio "controlled" the Wall is another matter; but he no doubt at least had the authority to give orders in an emergency without having to wait for authorization from the legionary legate at York (from Caracalla = at the same time the governor of Britannia Inferior) or the consular governor of undivided Britain further south.

The place-name: this is a conjecture by Mark W.C. Hassall, in Aspects of the Notitia (1976), 112f., edd. R. Goodburn and P. Bartholomew, who convincingly restores [Banna] after tribunus cohortis primae Aeliae Dacorum in line 44 in the Duke's list and inserts [tribunus cohortis secundae Tungrorum] before [C]amboglanna, making Banna the name of Birdoswald and Camboglanna that of Castlesteads; and replacing Petrianis after alae Petrianae in line 45 with Uxel(l)oduno, and Axeloduno in line 49 with Mais. This is now generally accepted, see e.g. A.L.F. Rivet & C. Smith, The Place-Names of Roman Britain (179) 220f. Cf. also in Britannia for 2004 on the Staffordshire pan, with another list of place-names from the western sector of the Wall.

And from M.G. Jarrett's article, cited by Prof. Birley above:

It [the unit] was in Britain in the Flavian period, probably arriving with the other reinforcements brought by Cerealis in 71. A tombstone (RIB 1172) which lacks the titles milliaria c.R. presumably relates to the first occupation of Corbridge or that of the earlier site at Beaufront Red House... An inscription from Carlisle which records a single torque (RIB 957) has no intrinsic dating evidence; but by a date late in the reign of Trajan a second torque had been awarded.  We have, therefore, evidence that under Trajan at the latest the unit was at Carlisle; by that time it had become milliaria... In the second scheme for Hadrian's Wall the ala Petriana was probably moved to a new fort at Stanwix, across the Eden from Carlisle. It is not attested on any inscription, though there is a lead seal (RIB 2411.84); the size of the fort is appropriate to an ala milliaria and there was no other such unit in Britain.  Nothing suggests that the ala ever left Stanwix... The ala Petriana was still at Stanwix when the Notitia was compiled.

In conclusion, if - as many leading archaeologists now believe - there was some kind of attempt along the Wall by local Dark Age warlords to retain a level of Roman military practice - and Arthur was, as I've theorized, situated someplace on the western end of the Wall, I can think of no better place than Stanwix for such a powerful leader to reside.