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Britannia Secunda or Britannia II (Latin for "Second Britain") was one of the provinces of the Diocese of "the Britains" created during the Diocletian Reforms at the end of the 3rd century. It was probably created after the defeat of the usurper Allectus by Constantius Chlorus in AD 296 and was mentioned in the c. 312 Verona List of the Roman provinces. Its position and capital remain uncertain, although it probably lay further from Rome than Britannia I. At present, most scholars place Britannia II in Yorkshire and northern England. If so, its capital would have been Eboracum (York).
The traditional arrangement of the late Roman provinces after Camden, placing Secunda in Wales. On the basis of modern archaeology, Prima at least reached as far north as Corinium.Another possible arrangement of the late Roman provinces, with Secunda in northern England
The placement and capitals of these late British provinces are uncertain, although the Notitia Dignitatum lists the governor (praeses) of Britannia II as being equestrian rank, making it unlikely to have been based in Londinium. The list of bishops who attended the 314 Council of Arles is patently corrupt but generally assumed to have mimicked the Roman administration: it seems certain one of the bishops was from Eboracum, even if his name ("Eborius") was a scribal error.
Camden
William Camden argued for a placement of Secunda in Wales and Charles Bertram's highly-influential forgeryOn the State of Britain placed Secunda gave it borders on the Dee and Severn; this was generally accepted from the mid-18th to the mid-19th century before being revealed as a fraud. It has been generally discounted since the discovery of inscriptions showing western England was part of Prima, with a possible capital at Corinium.
Ammianus records that in the year 369 Count Theodosius established or refounded the province of Valentia (further attested in the List of Offices) from lands recaptured from "the enemy". Its location is a matter of scholarly debate, but some place it at Hadrian's Wall in the area around Luguvalium (Carlisle). If so, it would have been formed at some point in the 4th century out of territory formerly administered from Eboracum. Others place it between Hadrian's Wall and the Antonine Wall or in Wales in the area around Deva (Chester); in both cases, some of the territory also may have been formerly administered from Eboracum prior to the reörganization.
Notes
Polemius Silvius's 5th-century Nomina Omnium Provinciarum gives six provinces, but Roman administration over the Orcades (Orkney) is generally discounted. Some modern scholars such as Birley, however, believe Maxima and Flavia were originally a single province Caesariensis which was later divided. This comports with Camden and some texts of Sextus Rufus, although they make the original province Britannia Maxima.
Valentia is generally treated as a later formation and placed variously beyond the Wall, around the Wall, and in Wales. It may, however, have simply been another name for the British diocese as a whole.
"Nomina Episcoporum, cum Clericis Suis, Quinam, et ex Quibus Provinciis, ad Arelatensem Synodum Convenerint" from the Consilia in Thackery (in Latin)
References
Frere, Sheppard (1967). Britannia: a history of Roman Britain. Cambridge: Harvard University Press. pp. 198–199.
As found in the Notitia Dignitatum. Provincial administration reformed and dioceses established by Diocletian, c. 293. Permanent praetorian prefectures established after the death of Constantine I. Empire permanently partitioned after 395. Exarchates of Ravenna and Africa established after 584. After massive territorial losses in the 7th century, the remaining provinces were superseded by the theme system in c. 640–660, although in Asia Minor and parts of Greece they survived under the themes until the early 9th century.
