thumb|Coin attributed to Carausius II / Censeris, with mostly clear obverse legend: DOMINO CNS CENSER[...]
Carausius II (or Censeris, or Genseris, or Censorius) may have been one or several usurper(s) in Roman Britain during the mid-fourth century AD. The suggestion of Carausius' existence relies entirely on the study of approximately twenty coins. No corroborating inscriptions, documents, or other contemporary historical accounts are currently known to exist.
The British Museum, citing the 1994 work by P. J. Casey, considers the coins in its collection (including at least one of the well-studied pieces) to be contemporary forgeries not representative of any legitimate historical figure.
Initial proposal
thumb|Plate image of the Evans coin, which is now held in the [[Ashmolean Museum.]]thumb|Coin of [[Constans, showing the prototype design to the Evans coin.]]The modern history of Carausius II began with a paper published by Arthur J. Evans in 1887. He wrote of a coin discovered in Richborough, the obverse of which he interpreted as "DOMINO CARAVƧIO CEƧ", (the AR, VƧI, and EƧ in ligature). He interpreted partial reverse legend as reading "DOMIN... CONXTA... NO," a fragmentary and abbreviated version of DOMINO CONSTANTINO.
Evans took special interest in the latter portion of the obverse legend, CEƧ, believing it to indicate that this coin depicted a previously unrecorded junior emperor. He noted that the coin's design was a reproduction of a Constantinian reverse type, originally minted from c. 348 to 355 AD. Unlike earlier barbarous imitations, however, which are typically dated contemporaneously to (or slightly later than) their official prototypes, Evans stated that "there can ... be little doubt that the coin with which we are at present concerned belongs to a considerably later date than its prototype."
Evans would conclude that the coin could be dated to approximately the same time period as the Ravenscar stone. He hypothesized that this Carausius may have been caesar under Constantine III (whose name, he claims, is referred to on the reverse as DOMIN[O] CONXTA[NTI]NO), and may have struck coins in Britain while Constantine was suppressing the revolt of Gerontius in Hispania in 409 AD.
thumb|The second coin, found in [[Richborough, 1924.]]
thumb|The "Unpublished British Museum coin", first published by Anscombe in 1927 but described in more detail by J. W. E. Pearce in 1928
Anscombe had several issues with Evans' interpretation of the first coin, foremost being his proposed chronology. Anscombe wrote that the years 407-411 AD are "...comparatively well illuminated historically, and the story of the Western Constantine the Third is quite precise ... in the history of Roman Britain in the fourth and fifth centuries." He did not comment specifically on either coin, but Sutherland would later regard these as tacit challenges to opinions considering Carausius/Censeris as a real historical figure. In the two decades since Anscombe's paper, an additional three coins had come to light, one being the Pierce coin published the year after Anscombe's work. The other two were both of unverifiable origin, although one, shown to Sutherland by Sir Charles Oman, was supposedly found somewhere in Oxfordshire.
In his paper, Sutherland largely disregards Anscombe's prior reinterpretation, reverting instead to criticizing Evans' work directly. He discusses four main issues with his interpretation: the coins' modules (size), evidence of overstriking, the titulature, and the designs.
All of the coins known to Sutherland, apart from one, were 18-20mm in size. He argued that this size was anachronistic to the Theodosian standard that would have been used in the early 5th century, whose small bronze coins were typically only 12-16mm in diameter. If a usurper or local leader were to arise and start striking coinage, it would be unlikely for them to arbitrarily abandon the standard already in use. Similarly, where two of the known coins showed clear signs of overstriking, he argued it would be unusual for a mint to do so atop "coins of obsolete size."
Carausius' supposed title of Caesar, while more sensical in the fourth century than the fifth, is still rather unusual for a completely independent usurper, as it implies some level of subservience to a more senior Augustus. On this, Stevens drew parallels to Vetranio, writing, "There is numismatic evidence to suggest that at this stage Vetranio contented himself with the title of Caesar, thus recognizing the primacy of Constantius as Augustus, and only assumed that of Augustus when pressure from Magnentius forced him to declare himself, whether seriously or not, against Constantius." The numismatic evidence that Stevens cites here is a single, unique coin, whose legends declare "VETRANIO NOB CAES" (Vetranio, most noble Caesar). While the coin's authenticity had been questioned by previous authors, he dismissed these claims as "not justified."
Stevens would further cite the contemporary work of Ammianus Marcellinus, who discusses the activities of Paulus following Constantius' defeat of Magnentius in 353. In late 353, Paulus was reportedly sent to punish several British militares accused of conspiring for Magnentius. Stevens speculates here that this "conspiracy" may have involved the army's illegal overthrow of Carausius II, whom he proposed could have been a legitimately-appointed Comes in Britain.
Kent (1957)
John Kent published the next major paper, where he helped to narrow the possible dating of these coins to the currently-accepted range of 354-358 AD. In this, he would publish a new coin, found near Stroud, as well as completely refute the "legitimate appointee" claims made by Stevens the previous year.
Kent would attempt to refine the dates primarily through presence/absence of similar coins in relevant, datable coin hoards. Like Sutherland, he would compare the modules of the known corpus (which had risen to at least 14 coins by this time) to official pieces, as well as drawing parallels to similar imitations of Magnentius. With these, he would conclude that the official smaller-module "fallen horseman" coin only began being issued in 353, with the "Carausius II" pieces (and other stylistically-linked imitations) following shortly after in 354. As for the terminal date, Kent looks at the undertypes of the many pieces which showed signs of overstriking. Several were overstruck on "GLORIA EXERCITVS" reverse types, but none (nor any similar overstruck imitations) were overstruck on the "SPES REIPVBLICE" reverse type, the latter of which can be definitively dated to after late 357 AD. As such, the terminal date for "Carausius II" coins is 358 AD.
thumb|The "SPES REIBVBLICAE" reverse type.
thumb|The "GLORIA EXERCITVS" reverse type.
Kent would mention that the unique "Vetranio Caesar" coin, upon which much of Stevens' argument rests, is a tooled forgery made from a genuine Alexandrian coin of Constantius Gallus. He further argues that, even if this coin were genuine, its existence would comment more on the politics of Constantius II, as Vetranio never controlled the mint of Alexandria.
While Kent concludes that while the chronology of the known coins can be confidently dated to 354-358 AD, he writes that he does not believe they represent a tangible usurper or leader in Britain.