Roman Britain's Pirate King: Carausius, Constantius Chlorus and the Fourth Roman Invasion of Britain

Introduction

The story of the late third-century

AD

‘pirate king’ Marcus Aurelius Mausaeus Carausius, his one-time chief supporter and later assassin Allectus and their North Sea Empire is one of the most enigmatic in the history of the Roman occupation of Britain. It features a cast of characters fit for any theatrical stage or Hollywood movie, including Carausius and Allectus themselves, their nemesis and western caesar Constantius Chlorus, the praetorian prefect Julius Asclepiodotus, and the western augustus Maximian, Diocletian’s first tetrarch.

The story of this lengthy usurpation as first Carausius, and later Allectus, sought to achieve imperial parity with Maximian and his eastern counterpart Diocletian is complex. It took place at the exact moment the Roman Empire was experiencing a period of huge transition which seriously impacted its political, economic and societal structures. Further, while many may have heard of their bids for the purple, few know the dramatic detail. Therefore, my chapter structure here is designed to first provide the reader with all the background necessary to understand the striking events I detail. Only then do I engage in the chronological narrative of the North Sea Empire. To that end Chapter One sets out how the Roman Empire at the end of the 3rd century

AD

had just traversed the ‘Crisis of the 3rd Century’, a series of cataclysmic events that rocked the very structure of the empire to its foundations. The third-century crisis also marked the beginning of a significant period of change in the Roman military on land and on sea, both of which were to play a major role in the story of the North Sea Empire and its demise. These are detailed in Chapter Two.

In Chapter Three I then tighten the focus to the by now two provinces in Britain ‒ Britannia Superior and Britannia Inferior ‒ showing how the broader crisis had specifically changed the nature of Roman-occupied Britain, setting the scene for Carausius’ usurpation. Chapter Four then begins the three chronological chapters covering the story of the North Sea Empire, this including an introduction to Carausius and his world, with his rise to power set against the decline of Romano-British naval capability after the disappearance of the Classis Britannica regional fleet. Next, Chapter Five covers the North Sea Empire at its height as it ‒ to a large extent ‒ saw off the abortive initial campaigns of Maximian to defeat recalcitrant north-western Gaul and the two British provinces. Chapter Six then tells the story of the fourth and final Roman invasion of Britain as the new western caesar Constantius Chlorus first reconquered Carausius’ Gallic territories, Allectus then assassinated Carausius, and finally Constantius Chlorus (together with Asclepiodotus) reconquered Roman-occupied Britain. The conclusion then considers the legacy of the protagonists in the story of the North Sea Empire, including the key role it was to play in the ultimate rise to power of Constantine I. This was an event that was to have profound implications, not only for the Roman Empire but also the world we live in today.

In terms of housekeeping, understanding the chronology of ancient Rome is important when considering the stories of Carausius and Allectus. Following the fall of the Republic at the end of the sanguineous civil wars of the 1st century

BC

, the first iteration of the Roman Empire was the Principate. This began in 27

BC

when Augustus was first acknowledged as emperor by the Senate. It lasted until

AD

284, with the accession of Diocletian and the end of the ‘Crisis of the 3rd Century’. The name Principate is derived from the term princeps (chief or master), referencing the emperor as the leading citizen of the empire. While not an official term, emperors often assumed it on their accession, it clearly being a conceit that allowed the empire to be explained away as a simple continuance of the preceding Republic. Then, given the major structural changes required to the nature of the Roman Empire as it exited the ‘Crisis of the 3rd Century’, the period that followed until the end of the western empire in

AD

476 is called the Dominate. This was a new, far more overtly imperial system; the title based on the word dominus which referenced lord, the emperor now effectively the equivalent of an eastern potentate. The stories of Carausius, Allectus, Constantius Chlorus and Asclepiodotus take place at the very beginning of this phase.

Next, with regard to the use of classical and modern place names I have (normally) used the modern name, referencing its Roman name at the first point of use. Meanwhile, where a classical name for a role, position or event is well understood I use that; for example, legate (general or commander), though for those less well-known I use the modern version.

Meanwhile, military installations played a key role in the story of the North Sea Empire. In that regard I have used the current size-based hierarchy as a means of describing their size as they occur in the narrative. Starting with the largest, these are twenty hectare-plus legionary fortresses for one or more legions, then twelve hectare-plus vexillation fortresses holding a mixed force of legionary cohorts and auxiliaries, next one hectare-plus forts for outpost garrisons, and finally fortlets for part of an auxiliary unit. A military settlement associated with such fortifications is called a canaba when connected with a legionary fortress and a vicus elsewhere.

In terms of the built environment, this again features heavily in the story of Carausius and Allectus. Here, larger towns are referenced as one of three types. These are coloniae, chartered towns for military veterans (in Britain, for example, Colchester); municipia, chartered towns of mercantile origin (in Britain, for example, St Albans) and civitas capitals, these last the Roman equivalent of a county town featuring the local government of a region (in Britain, for example, Canterbury). Settlement below this level is referenced as either a small town (defined as a variety of diverse settlements which often had an association with a specific activity such as religion, administration or religion), a villa estate or a non-villa estate.

An understanding of the social structure of Roman society is also very useful when considering the North Sea Empire. In terms of ranking within the aristocracy, at the very top was the senatorial class, said to be endowed with wealth, high birth and ‘moral excellence’. There were still around 600 senators in the later 3rd century

AD

, despite the reforms of Diocletian. Those of this class were patricians, a socio-political rank, with all those below including other aristocrats called plebeians. Interestingly, we know of no senator who originated in Britain. Next was the equestrian class, having slightly less wealth but usually with a reputable lineage. They numbered well over 30,000 across the empire in the later 3rd century

AD

. Finally in terms of aristocracy there was the curial class, with the bar set slightly lower again. The latter were usually merchants and mid-level landowners, making up a large percentage of the town councillors in the Dominate Empire. Below this, one then has freemen who were free in the sense that they had never been slaves. They included the majority of smaller-scale merchants, artisans and professionals in Roman society. All the above classes were also full Roman citizens whether they came from Italy or not following Caracalla’s

AD

212 Constitutio Antoniniana (Edict of Caracalla) which made all freemen of the empire citizens. Further down the social ladder one then had freedmen, former slaves who had been manumitted by their masters either through earning enough money to buy their freedom or for good service. Once free, these former slaves often remained with the wider family of their pater familias head of family or former owner, frequently taking their name in some way. As long as the correct process of manumission was followed, freedmen could become citizens, though with fewer civic rights than a freeman including not being able to stand for the vast majority of public offices. Their children were freemen. Many freedmen became highly successful and, given that they were not allowed to stand for public office, they found other ways to celebrate their lives. A common example was the provision of monumentalized funerary monuments. Meanwhile, on the bottom rung of society were slaves.

Meanwhile, as in all works regarding events in the ancient world, the sourcing of accurate data is very important, and here with Carausius and Allectus’ North Sea Empire numismatics plays a key role. It was Carausius who founded Britain’s first bespoke Roman mint in London and who, through the quality of his coinage, sought to allude to an earlier era of Roman glory, his issues often referencing a Virgilian past. For Allectus, the usurper of the usurper, that was even more the case. Such is the importance of coin production in both pitches for legitimacy that the beginning of Chapter Four is devoted to the subject, shedding new light on how Roman leaders validated claims to power through the medium of their coinage. In this we are very fortunate that a number of well-known coin hoards from Britain feature significant quantities of Carausian and Allectan coins, many hidden away by elite landowners keen to distance any allegiance with the failed usurpers.

Meanwhile Constantius Chlorus, the ultimate victor in this late third-century

AD

Romano-British power struggle, is also well-referenced in the numismatic record given that he was widely lauded as the restitutor of imperial fortunes in the north-west of the empire. In particular, the well-known gold Arras medallion celebrating his success in defeating Allectus and saving London from its volatile Frankish defenders is highly significant given that it features the first ever visual representation of London.

Compared to such widespread numismatic evidence, contemporary written historical data for the North Sea Empire is scarce. We are now beyond the earlier Principate phase of empire when we can rely on the likes of Cassius Dio and Herodian to provide insight into the lives of the great Romans before and of their day. Even the anonymous Historia Augusta, while most likely written during and after the lifetime of Carausius and Allectus, finishes with the lives of the emperors Carus, Numerian and Carinus, the latter dying in

AD

285. In that regard, while it can provide insight into the events that set in train Carausius’ dramatic bid for power, it is silent on the events themselves. For near contemporary insight we are left with a number of the later Latin chroniclers, principally Aurelius Victor and Flavius Eutropius who wrote in the middle of the 4th century

AD

and Paulus Orosius who wrote in the early 5th century

AD

. The first two of these (and given their use as sources by the third, that too by default) seem to have used as a key resource the so-called Kaisergeschichte hypothetical set of short histories, now lost, which Burgess (1993, 491) argues was probably written between

AD

337 and

AD

340. Their common wording and phrasing, and facts and errors imply this. All three sources feature key passages in their work about Carausius, Allectus, Constantius Chlorus and Asclepiodotus.

Meanwhile, for insight into the transition taking place in the Roman military at the time of the Carausian Revolt we do have some contemporary commentary which has proved useful; for example, with the early Christian writer Lucius Caecilius Firmianus signo Lactantius. His On the Deaths of the Persecutors and other works were written while professor of rhetoric in Izmit (Roman Nicomedia) in modern Turkey, where he had time to reflect first-hand on the early phases of the Dominate Empire, having served in the court of Diocletian and been an advisor to Constantine I. Note I have discounted as useful sources the various medieval authors who narrate the story of Carausius and Allectus from the time of Bede onwards. Most feature obvious mistakes, making interpreting the few reasonable examples of contemporary history we have even more problematic. Examples include the Byzantine twelfth-century

AD

chronicler Johannes Zonaras, who refers to Allectus as Crassus throughout his narrative.

Contextually, while the above detailed contemporary accounts regarding Carausius and Allectus do seem few in number, they do bring to an end a very barren period in coverage of this far-flung corner of the empire in the historical record following the Severan attempts to conquer the far north in

AD

209 and

AD

210. Indeed, as Casey explained in his detailed analysis of the roles played by the usurpers in north-western Gaul (1970, 283): ‘The episode of the usurpation of Carausius and Allectus has long attracted scholarly attention, not least because it is a light at the end of the long dark tunnel which comprises the history of Britain in the 3rd century

AD

.’

Importantly, to these written sources we can also add a series of key panegyrics gathered together within a collection called the XII Panegyrici Latini (or Twelve Latin Panegyrics). Such orations were delivered in high praise of an individual and were a common feature of the Roman celebration of the imperial cult. They are useful providing one takes into account the obvious bias in them which is even more evident than is common in most ancient historical sources. The authors of the majority in this collection are anonymous, though most were likely Gallic in origin given this was a region of the empire with a long association with rhetoric. The earliest, and one of the few attributed an author, was composed by Pliny the Younger around

AD

100, while the rest were written much later between

AD

289 and

AD

389. The original manuscript of this collection was first discovered in

AD

1433 and has since been lost, though the text has fortunately survived intact. Five of the panegyrics are relevant here, two of which unusually name the author.

The first is dated to April

AD

289 and was given in Trier (Roman Augusta Trevevorum) in honour of the western augustus Maximian, this marking the double celebration of both his birthday and the founding day of Rome. The oration was most likely written by Mamertinus, the emperor’s magister memoriae private secretary, given that Maximian was present when the oration was given. This is an important piece of evidence as the speech was actually delivered in the midst of the Carausian Revolt rather than after the event. In the oration Maximian’s victory in North-West Europe over the ‘pirate’ Carausius is specifically referenced, as is the latter’s subsequent abandonment of his first mint in Rouen (Roman Rotomagus, though see discussion in Chapter Four about whether this was actually temporary and mobile) and his subsequent flight to Britain. The relevant passage in the panegyric ends by detailing Maximian’s future plan to assault the breakaway provinces of Britannia Superior and Britannia Inferior, later to prove so spectacularly unsuccessful. This entire narrative is hagiography at its finest given that north-western Gaul, centred on Boulogne-sur-Mare (Roman Gesoriacum), remained a core Carausian territory until

AD

293 when it was finally reconquered by Constantius Chlorus. It therefore only references Maximian’s initial response to Carausius’ usurpation when he targeted the latter’s territories around Rouen to the south.

Maximian’s failure in his early attempts to defeat Carausius are next evident in the panegyric of

AD

291, again delivered to the augustus in Trier and this time definitely written by Mamertinus. The key insight here is that while there is a reference to the building of the new fleet needed to invade Britain, there is no mention of the two British provinces at all. An evident and very embarrassing imperial failure was thus glossed over, in a manner worthy of a modern political spin-doctor.

The third relevant panegyric is dated

AD

297 and specifically celebrates the reconquest of Britain by Constantius Chlorus in

AD

296. It was delivered to the caesar in his imperial residence in Trier and goes into graphic detail about his

AD

293 defeat of Carausius in north-western Gaul, and his subsequent victories against Allectus which saw the North Sea Empire finally defeated. It also provides great insight into how such orations were part of a wider public relations exercise by Maximian and Constantius given the language used matches that featured on the coinage minted to celebrate victory; for example, on the Arras medallion. This panegyric should not be confused with that given a year later by Eumenius, teacher of rhetoric at Autun (Roman Augustodunum), in honour of the governor of the Gallic province of Gallia Lugdunensis. While also detailing the exploits of Constantius Chlorus and the other tetrarchs, this doesn’t mention Carausius or Allectus, perhaps to spare the blushes of Maximian.

The final oration in the Panegyrici Latini referencing Carausius is that written by an anonymous author and delivered to Constantius’ son and successor Constantine I in Trier in

AD

310 or

AD

311 on the occasion of his quinquennalia (the fifth anniversary of accession) and also to celebrate the founding day of the city. This lengthy oration contains a description of the appearance of the Sun god Apollo to Constantine that has frequently been interpreted as a model for his later Christian vision on the night before his victory over Maxentius at the Battle of Milvian Bridge in

AD

312. Crucially for this narrative, the panegyric also contains a summary of his father’s defeat of Carausius and Allectus.

It should be noted here that all the above literary references are broadly critical of Carausius and Allectus. With regard to the traditional historical sources this is not surprising when set against the achievements of the great, as contemporary commentators saw it, Diocletian. This negative spin is even more evident in the panegyrics given that they don’t even mention the protagonists of the North Sea Empire by name, referring to them by a variety of derogatory periphrases and epithets including desperate creature, pirate (as mentioned, and featured in the book title) and robber. This was very normal in the Roman world, where such orations to Maximian and Constantius Chlorus focused on their own martial prowess rather than that of their usurping opponents. Further, enemies of the state and criminals (as Carausius and Allectus were later considered) frequently went unnamed after the event, this being a means of despoiling their achievements in life. There is also a darker context here, this with reference to the way in which the Romans remembered the dead. Burial practice and remembrance of the deceased were very important in the Roman world, where an individual’s post-mortem ‘existence’ in the afterlife was eased by the celebration of their achievements in life by the living. Therefore, ensuring that the dead remained unnamed was a certain way of guaranteeing their damnation once deceased.

Meanwhile, on a final note on contemporary written sources, one can also add the various contemporary or later Roman travel itineraries and office-holder lists; for example, the Tabula Peutingeriana, Antonine Itinerary, Ravenna Cosmography and Notitia Dignitatum.

In terms of modern sources, while the above detailed contemporary writers had little overtly positive to say about Carausius and Allectus, more recent commentators have been more benign. The story of their North Sea Empire was initially rehabilitated through the work of William Stukeley, Maurice Johnson and other eighteenth-century antiquarians. Writing at a time when Britain was faced with invasion from the Continent, they portrayed Carausius in an almost Arthurian light as a symbol of heroic resistance. Since that time interest has gathered apace, certainly in academic circles, such that today there is a considerable canon of literature to access. In particular, those with a focus on numismatics have proved invaluable given the importance as detailed of coin production in the stories of Carausius and Allectus. The most important work remains Sam Moorhead’s 2013 A History of Roman Coinage in Britain, given the breadth of his widespread analysis together with his later 2014 and 2015 reviews of Carausian and Allectan coinage in Revue Numanistique and ARA News. Meanwhile, the 1984 edition of the British Numismatic Journal also contained four very important articles on coinage of the period; these by Roger Bland, Andrew Burnett (individually and with John Casey) and C.E. King. A further 1998 paper by C.D. Lloyd in this esteemed journal has also proved most useful, as has Guy de la Bédoyère’s 1998 article in The Numismatic Chronicle.

More broadly, other key modern works specifically on Carausius and Allectus include John Casey’s 1995 Carausius and Allectus: The British Usurpers and his earlier 1977 Britannia paper Carausius and Allectus – Rulers in Gaul. Norman Shiel has also been a prolific writer on the usurpers with, for example, his 1977 British Archaeological Report The Episode of Carausius and Allectus: The Literary and Numismatic Evidence, and his earlier 1975 Durham University paper The Episode of Carausius and Allectus, with Particular Reference to Numismatic Data. To these we can add Hugh P.G. Williams’ 2004 Carausius: A Consideration of the Historical, Archaeological and Numismatic Aspects of his Reign, this being another fine British Archaeological Report.

For other modern sources, I have accessed the widest possible range. In the first instance this has included my own academic research over the last seventeen years through my MA in War Studies from KCL, MA in Archaeology from UCL and PhD in Classics and Archaeology from the University of Kent (where I am an Honorary Research Fellow). Additionally, my recently published works on Roman themes have proved a fertile source of new information on the Roman Empire in the later 3rd century

AD

. These include the 2016 Sea Eagles of Empire: The Classis Britannica and the Battles for Britain (a key work here given the importance of naval