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Celtic Kingdoms of the British Isles

Celts of Britain


Roman Empire Britannia (British Isles)

The history of the British Isles from the end of the most recent ice age to the formation of the united Anglo-Saxon kingdom forms several stages and covers a good deal of conflict. It starts with the Early Cultures which appear prior to the Iron Age. Then the Celtic occupation of Prydein leads up to the Roman incursions and the creation of Roman Britain. Subsequent decline generates the Post-Roman period in which all stories of Arthur are contained, but this also covers the gradual loss of Celtic power in the land and its marginalisation on the western and northern fringes.

MapFrom AD 43 to around AD 79 the Romans invaded and conquered the south and east of Britain, although at times their hold on the island appeared tenuous. From there they extended their conquests to cover modern Wales and the north, areas in which their hold would appear even more tenuous, especially in modern Scotland. Aulus Plautius was appointed by Rome as the first Roman Governor of the island in AD 43, and it was he who commanded the legions and their conquests (see the map of most of Europe's tribes around the first centuries BC and AD to view the location of Britain's tribes in relation to all other Celts).

FeatureFor the entire period of the Roman occupation of Britain, tradition still dictates that high kings held some form of power or influence in the country. Much of this tradition was written down by Nennius (see feature link) and Geoffrey of Monmouth, and much of it is very easy to dismiss. However, the concept of a high king seems to have re-emerged in the fifth century AD, and perhaps for some time after the initial Roman conquest it also persisted, apparently with the Silures having predominance over the other conquered British tribes (if Nennius et al are to be believed at all).

Since the Silures had fought so hard against Rome, perhaps they had earned the right to proffer titular high kings in place of the Catuvellauni who had been so quickly defeated, and so completely defeated. Many of the later Roman-period names which are claimed by much later writers as high kings were nothing of the sort. They were often Roman emperors, Roman senior commanders in Britain (such as Magnus Maximus), or even Roman usurpers (such as the Carausius of 286). In fact, it seems that anyone who could rule all of Britain in defiance of Rome itself was eligible.

Roman Canterbury

(Information by Peter Kessler, with additional information by Edward Dawson, from The Oxford History of England: Roman Britain, Peter Salway, from Roman Britain: A New History, Guy de la Bédoyère, from the Historia Brittonum (The History of the Britons), Nennius (J A Giles, Ed & Trans, 1841, published as part of Six Old English Chronicles (Henry G Bohn, London, 1848)), from History of the Kings of Britain, Geoffrey of Monmouth, from A History of the English Church and People, The Venerable Bede (Leo Sherley-Price translation - revised by R E Latham), from Roman and Anglian Settlement Patterns in Yorkshire, M L Faull (1974), from Life of Agricola, Tacitus, and from External Links: Irish Archaeology, and Liber Pontificalis (The Book of the Popes), available via the Internet Archive.)

43 - 51

Caratacus fights from 43-51, first in the territories of the Cantii and the Catuvellauni, from where he takes shelter with the southern Dobunni. He then moves to the Silures and the Ordovices, before being defeated in battle for the last time.

Map of Britain AD 10
By the end of the first century BC and the start of the first century AD, British politics often came to the attention of Rome, and the borders of the tribal states of the south-east were pretty well known (click or tap on map to view full sized)

43 - 51

Caratacus / Guiderius

High King of the Britons in opposition to Rome.

Caratacus subsequently takes shelter with the Brigantes, but is betrayed and handed over to the Romans. Taken in chains to Rome, Emperor Claudius pardons him and his family, and they live out their lives there. The Demetae appear to be subdued in AD 51 but complete conquest of the west (modern Wales) is not effected until AD 79. The Dumnonians are subdued by AD 55, and probably the neighbouring Cornovii with them.

59 - 61

Once Prasutagus of the Iceni dies, the Romans begin to ignore the terms of the Iceni's client-statehood. Stirred up by imperial heavy-handedness, Boudicca leads a powerful Celtic uprising involving the Iceni, the Trinovantes and other tribes. It results in the loss to the Romans of lower eastern Britain.

After sacking and burning Camulodunum, Londinium, and Verulamium (St Albans), the Celts are confronted by a fresh Roman army under Roman Governor Gaius Suetonius Paulinus and are defeated. Boudicca's fate is unknown, but it is presumed that she commits suicide rather than allow herself to fall into Roman hands.

Boudicca coin
Two sides of a coin issued about AD 61 are shown here, featuring the face of Boudicca on the obverse and a horse on the reverse - horses were valuable commodities amongst the Britons

70 - 125

FeatureA period of intense building work following the Boudiccan revolt takes place in London during the Flavian period in the Roman empire, doubling the size of the municipium and turning it into one of the greatest of cities in Britain (see feature link). This is the period in which London truly becomes a capital city.

74 - 125

Marius / Meric/ Merius / Meurig

High King. Ruler of the Silures.

78 - 79

The Roman Governor, Julius Agricola, continues his campaign from the territory of the Ordovices and breaks the Deceangli in Mona (Anglesey). Roman troops are withdrawn from the territory of the Dumnonii to support the campaign.


Archaeological evidence from at least this date onwards suggests the presence of Romans in Ireland. One candidate is Stoneyford in County Kilkenny, which is navigable from Waterford on the Nore, while Loughshinny in County Dublin is another candidate.

Stoneyford's heavily-defended fort has been identified as a significant Roman beachhead, built to support military campaigns in the first and second centuries AD. Later developing into a large trading town, it contains Roman coins stamped with the names of various emperors from Titus onwards. The Roman presence would seem to last until at least AD 138.

Sequential Maps of Roman Britain AD 43-425
The Roman invasion of Britain began late in the season, using three divisions which swiftly conquered the south-east before more slowly penetrating the west and north to bring all of England and Wales under their control, as shown in this series of sequential maps (click or tap on map to view full sized)

80 - 84

The Roman Governor of Britain leads two invading columns into Lowland Scotland, The force sets up permanent garrisons in its wake. In AD 81 the Forth-Clyde line is secured, perhaps slightly south of the later Antonine Wall. The following year, the Romans secure the western coast up to the Clyde to contain the tribesmen there (the Damnonii, Selgovae, and Novantae) and perhaps prevent Irish landings.

Within the Caledonian heartland, firstly north of the Firth of Forth (in AD 83) and then at Mons Graupius (in AD 84), the Romans win victories over what they call the 'Caledonides' led by Calgucus (probably involving the tribal grouping of the Creones and their neighbours along the western coast), and then fight a decisive battle to end the campaign.

fl 100 - 105

Arviragus / Arbitrages

Hostile, chariot-borne British chieftain, mentioned in Juvenal.

c.100 - 105

Arviragus seems to have been a chief of the northern Brigantes who may be responsible for the burning of the Roman auxiliary fort at Corstopitum (Corbridge), as well as others at this time (including Trimontium, now known as Newstead), as the British tribes of Lowland Scotland stage a major uprising.

By AD 100 the Romans give up the north, and fully establish their defences along the Tyne-Solway line. Geoffrey of Monmouth claims Arviragus as the son of High King Cymbeline and the father of Marius of the Silures, probably in an attempt to link together all three 'high kings' in a single dynasty.

Queen Cartimandua hands over Caratacus
This print by F Bartolozzi which sits in the British Museum depicts Cartimandua betraying the movement for British independence in the face of the Roman invasion by handing over a chained Caractacus to the Romans

c.118 - 120

That Britain is the scene of some serious warfare is not in doubt. However, although the weight of evidence points to an invasion from outside the province (most likely from the highlands), this is by no means certain.

FeatureEmperor Hadrian visits and authorises the construction of a stone wall along the Tyne-Solway line in 121-122 as part of his defensive reorganisations to divide the barbarians from the Romans (see feature link). Some forts are maintained to the north of the western section, once 'Hadrian's Wall' is completed around 127.

122 - 138

The Tungri are first mentioned in connection with Hadrian's Wall, on a stone at the Carrawburgh fort which is dated to this period. The First Cohort of the Tungri is mentioned in a total of ten inscriptions, and as well as postings to Carrawburgh and Housesteads they also do turns of duty at the forts of Chesterholm and Castlecary on the wall.

The Tungri are joined by a detachment of Varduli cavalrymen from northern Iberia and Batavi from the Netherlands. The Cilurnigos clan of Astures Iberians later forms the Ala II Asturum cavalry unit which is stationed at Chesters Roman Fort on Hadrian's Wall. The camp there is named Cilurnum after them.

125 - 154

Coilus / Coel

Son of Marius. Puppet king, according to the Damnonii exiles.

c.125 - 130

A fairly serious fire occurs in Londinium, presumably from accidental causes. The later archaeological record shows a clear burn layer for this period. Rapid action is taken to rebuild the damaged sections of the city.

Roman Londinium
A recreation of Roman Londinium showing the legionary fort (lower centre) and the River Walbrook running from the north wall (on the left) into the Thames

140 - 143

The Romans move north to the Forth-Clyde line, roughly the southern Caledonian boundary, reoccupying Lowland Scotland and beginning construction of the more basic Antonine Wall (curiously, this takes place immediately after a revolt by the Brigantes is put down). Coins announcing a victory are issued in late 142 or early 143 to mark the event.


Corvus of the Damnonii apparently announces the creation of the kingdom in 148, raising a following of British patriots. He dies fighting the Romans in 184 but his kingdom remains outside direct Imperial control, one of four such kingdoms. The others are probably those of the Votadini and Selgovae Britons, and the Novantae Caledonians.

154? - 180?

Lucius / Llewrug Mawr

Son of Coilus. Ruler of the Silures. Introduced Christianity?


In response to a growing need for troops elsewhere, the Romans seem to abandon the northern, Antonine Wall, although some outpost forts may remain in use until at least the 180s. A fort excavated at Camelon, just two kilometres or so east of Falkirk, seems to confirm a withdrawal date of this time.

FeatureHadrian's Wall itself is certainly still garrisoned, as archaeology has proven (see feature link). The tribal kingdoms of the north remain on friendly terms, now recognised as official buffer states.

165 - 180

Plague enters Rome from the east, brought back by returning legionaries. It quickly spreads throughout the empire and is generally known as the Antonine Plague. When it arrives in Britain it strikes hard. In 2004, archaeologists uncover the remains of ninety-one men, women, and children dumped haphazardly into a mass grave at Glevum in the territory of the former Dobunni tribe.

Glevum plague victims
The widespread Antonine Plague which killed these people and resulted in the use of mass graves is thought to have been smallpox

c.170 - 175

The coastal tribe of the Chauci have long been sea raiders, but by the late second century the problem has grown much worse. Now Chauci raids are as bad as the better-known Saxon raids of the fourth century, but what is assumed to be their last recorded attack happens in this period.

Archaeological finds show a layer of destruction along a great deal of the North Sea and Atlantic coast of Europe, between Belgica and southern Gaul, and in eastern Britain, well inside the territory of modern Essex.

The Chauci are prime suspects for the raids, and Rome responds with improved defensive measures over the following thirty years or so. Fortifications are put in place at sites including the Iceni civitas of Venta Icenorum (modern Caistor-by-Norwich), the Trinovantes town of Caesaromagus (modern Chelmsford), and the civitas of the Canninefates, Forum Hadriani (modern Voorburg). This is the start of the system which will develop into the Saxon Shore in Britain.


FeatureThe Roman emperor, Marcus Aurelius, defeats the Iazyges tribe of Alani (or Sarmatians). He takes them into Roman service and settles them in northern Britain, at Ribchester, south of Lancaster. The Alani are assigned to the VI Legion Victrix, commanded by the Alani warlord who is renamed Lucius Artorius Castus (an unlikely candidate for the battle leader, Arthur, of the fifth century - see feature link).

Roman-era skull from the Walbrook
Even after the Roman occupation of Britain, a number of British customs seem to have survived, such as using human heads as ritual objects, with this skull being placed in the River Walbrook (which flows through the very centre of Londinium)

178 - 180?

Lucius writes to Pope Eleutherius of the Roman Church requesting to become a Christian. The event is first noted in the sixth century Liber Pontificalis, and Bede repeats it, after which Lucius is widely acclaimed as being responsible for introducing Christianity into Britain.

FeatureHis story is expanded by later writers, when he is claimed as the son of former High King Coilus and is credited with founding the church of St Peter upon Cornhill in London (the church carries a plaque to the effect, dating the event to 179 - see feature link).

In fact, Lucius may be a misreading of Lucius Aelius Megas Abgar IX, Roman client king of Osroene. However, whether through the involvement of Lucius or not, a British Church does apparently begin to make its presence felt in the country during this century.

Geoffrey of Monmouth claims a date of death for Lucius of AD 156. His home has been in Glevum, suggesting perhaps that it falls within the edges of Silures territory or that they may be a dynastic link between the Silures and the Dobunni. Lucius dies without an heir to succeed him, and the (legendary) high kingship falls vacant. Subsequently, many Roman figures are listed as high kings, some of whom certainly do hold positions of power in Britain, either as regional commanders or usurpers.

Nemausus (Nimes)
Times were tough in the mid-fifth century, and Britain's resources were not what they had once been, what with barbarians at the door and withdrawal from the fading Roman empire, so Glevum's amphitheatre had to be made defendable (Nemausus (Nimes) amphitheatre is shown here)

180 - 185

A serious attack by the northern peoples takes place upon the death of the Roman emperor in 180, either from north of Hadrian's Wall into the province itself (with the Damnonii being an especial candidate), or from beyond the Antonine Wall to attack and devastate Roman forts in Lowland Scotland. Either way, it seems probable that in 184-185 the Roman Governor, Ulpius Marcellus, campaigns with two legions into Lowland Scotland and beyond the Forth-Clyde line into Caledonia.

From the point of view of the high kingship, it seems perhaps more than coincidental that this attack, or uprising, occurs straight after the presumed date of death for Lucius. Could he have provided a voice of reason and complicity with the Romans which the northern peoples chose to observe during his lifetime?

Geoffrey of Monmouth has the attack being lead by a British noble man named Sulgenius. Ultimately he captures York and is besieged there. He kills Severus in combat but is mortally wounded himself (which would suggest that the uprising lasts for about thirty years, as the death of Severus is in 211).

Male Romano-British dress
Costume illustration of a Romanised British man (left) and a Romanised British aristocrat, with each wearing leather Gladiator sandals, one pair with a thong fitting and the aristocrat with sandals with many straps (from Hope's Costume of the Ancients).

193 - 197

Decimus Clodius Albinus

Rival emperor of Rome. Governor of Britain.


After an attempt to have Albinus assassinated fails, Emperor Severus marches on Gaul to meet Albinus' forces. The final battle is a close-run affair, but Albinus does not survive the encounter. Severus immediately divides the single province of Britannia, probably in a temporary fashion at first, with division being confirmed within two or three years.

198 - 217

Bassianus (Caracalla)

Son of Septimus Severus. Emperor of Rome.


In 2015, archaeologists examining a site in the Roman city of Corinium (modern Cirencester) find a rare burial with tombstone still in place (although it had fallen before being covered by the debris of centuries). Possibly the first of its kind to be discovered in the British Isles, the tombstone is found near skeletal remains thought to belong to the person named on its inscription, Bodica, aged twenty-seven.

Bodica is a Celtic name, and the quality of the burial shows that some wealth is involved. The bodies of three children are also found in the 'family burial plot'. The tombstone contains an empty space for another inscription, presumably that of the widowed husband who could potentially marry again and later be buried elsewhere.

Bodica tombstone of Corinium
The tombstone which was excavated intact from its original location in Cirencester is inscribed 'To the spirit of the departed Bodica [or Bodicaca], wife, lived for twenty-seven years', although the space left for her husband's name was never use

Bodica's name is further proof that the native Britons have continued to honour their fallen heroes of the resistance against Rome by naming their children after Boudicca, Caratacos, Cunobellinos, and so on.

Linguistically, could Boudicca be an indication that the letter 'c' (with a 'k' sound) is repeated? The use of Boudicaca points to this being a possibility. (Note: Briton names ending in '-us' are Romanised. The correct suffix is '-os', the same as in Greek, and both are descended from the reconstructed proto-Indo-European suffix '-az'.)

209 - 212


Brother. Joint emperor of Rome. Murdered by Caracalla.

209 - 211

Roman Emperor Severus leads a campaign against the Caledonii in person, making his headquarters (and the centre of the Roman empire for three years) at Eboracum (York), but ill-health means he has to hand control of its day-to-day conduct to Caracalla.

Roman Britannia (British Isles)
Incorporating the Empire of the Gallic Provinces
AD 260 - 274

Rome conquered the south and east of Britain between AD 43 to around AD 79. From there they extended their conquests to cover modern Wales and the north, although their hold over the north was never anything more than tenuous and temporary. The senior commander of the first wave of invasion, Aulus Plautius, was confirmed as the first Roman Governor of the isles in AD 43.

Imperial territory since that initial advance into modern Scotland later ebbed back to a line which was marked by the Antonine Wall, and then another which was marked by the second century Hadrian's Wall. Rome seemed to be continually opposed in the north by the Damnonii, but in the third century AD even more serious problems arose within and without the empire, those of increasingly frequent rebellions and major population movements across the Rhine border.

In the second half of the third century, and against a backdrop of a series of Roman governors in Britannia Superior and Britannia Inferior about whom very little is known, crisis struck the weakened empire when the Rhine frontier collapsed completely in the face of Alemanni attacks. To make matters worse, Britain and Gaul revolted against Rome's faltering control when Marcus Cassianus Latinius Postumus, second-in-command on the Rhine, murdered the praetorian prefect, Silvanus, and declared himself emperor. The Roman provinces in Germany, Gaul, Iberia, and Britain and their armies supported him.

For the next thirteen years the whole of the north-western part of the empire was run as an independent but fully Roman state with its own series of emperors. It is generally known as the 'Empire of the Gallic Provinces' (Imperium Galliarum, or the 'Gallic Empire'). A senate was established, as was a praetorian guard. Its leaders are shown in red text to highlight them against the more normal backdrop of everyday events in the British Isles.

Roman Canterbury

(Information by Peter Kessler, with additional information by Edward Dawson, from The Oxford History of England: Roman Britain, Peter Salway, from Roman Britain: A New History, Guy de la Bédoyère, from the Historia Brittonum (The History of the Britons), Nennius (J A Giles, Ed & Trans, 1841, published as part of Six Old English Chronicles (Henry G Bohn, London, 1848)), from History of the Kings of Britain, Geoffrey of Monmouth, from A History of the English Church and People, The Venerable Bede (Leo Sherley-Price translation - revised by R E Latham), from Roman and Anglian Settlement Patterns in Yorkshire, M L Faull (1974), from Life of Agricola, Tacitus, and from External Links: Irish Archaeology, and Liber Pontificalis (The Book of the Popes), available via the Internet Archive.)

260 - 269

Marcus Cassianus Latinius Postumus

Usurper emperor of Rome. Murdered by his troops.

260 - 263

Postumus works hard to fulfil the duty which has been given to him through the support of his troops. He gradually restores peace to the provinces in Western Europe, defeating Frankish and Alemanni threats in 262 and 263 respectively. The peace which follows, however, seems to show Postumus as being unwilling to take Rome.

Sequential Maps of Roman Britain AD 43-425
Emperor Severus visited the provinces to lead a campaign in person against the Caledonii and Maeatae in 209-211, pursuing a scorched earth policy to try and bring the ephemeral tribesmen to battle (click or tap on map to view full sized)



Would-be usurper of the Imperium Galliarum. Executed.

269 - 263

Laelian commands two legions from his headquarters in Mainz. After repulsing an attempted incursion by seemingly unspecified Germanics, he declares himself emperor in opposition to Postumus. His 'reign' lasts about three and-a-half months before Postumus defeats him and his is executed. Unfortunately, the successful Postumus is killed by his own troops, seemingly for preventing them from looting Mainz.



Usurper Roman emperor. Elected at Mainz. Lasted 2-3 mths.

269 - 270


Usurper Roman emperor. Imperium Galliarum praetorian.

268 - 282

The threat of Saxon raids along the east coast appears to become serious in this period. Major improvements are made to the coastal defences in south-eastern Britain as a result.

Two forts in the system, Bradwell-on-Sea and Walton Castle (in Suffolk) are near Colonia, capital of the Trinovantes. They probably belong to the second half of this period. Colonia lies less than sixteen kilometres from the coast and, although protected to an extent by those two forts, is still vulnerable to sea-borne raiders, especially via the mouth of the River Colne. Three coin hoards from the Colchester area, all dating to about 275, attest to the widespread feeling of insecurity at the time.

Caer Colun (Colchester)
The artist's impression of the Roman city of Camulodunum (Romano-British Caer Colun, modern Colchester) shows it in its heyday, before some gates were sealed up but after its walls - the earliest city walls in Britain - were erected in order to safeguard it from any further Boudiccan-style revolts

270 - 274

Esuvius Tetricus (I)

Usurper emperor of Rome.

270 - 274

Tetricus (II)

Son. Caesar. Life (and senatorial rank?) spared by Aurelian.



Usurper emperor of Rome. 'Ruled' for four days.


FeatureEvidence for the reign of Domitianus is scant. Probably acclaimed in northern Gaul either towards the end of 270 or early in 271, his coins (three by 2022) are to be found in Gaul and Britain (Oxfordshire - see feature link). His fate is unknown, but it remains possible that his troops murder him and declare for Tetricus instead.


The Imperium Galliarum collapses when Aurelian defeats its military power in battle at Châlons, the capital of the Catalauni Gauls. Tetricus has already switched sides, and is permitted to pursue a useful and distinguished career in Roman life. The governance of Britain is rearranged, creating the Diocese of the Britains between now and 314 and sub-dividing the existing two provinces into four.


FeatureVandali and Burgundians who had crossed the Rhine to invade the Roman empire are defeated by Emperor Marcus Aurelius Probus and are resettled in Britain. The emperor is generally successful in defeating several rebellions and external invasions but, despite his good reputation, he is still murdered by his own troops. Britain's Octavius may hold a position of power within the island's administrative structure (see feature link).

Vandal officer Stilicho
Stilicho is probably one of the most famous Vandal soldiers, serving as magister militum from the 380s until he was executed by his masters in 408

fl c.283

Octavius / Eudaf Hen

King of Ewyas, a successor state to the Silures.


Roman emperor Diocletian takes the title of Britannicus Maximus, and it seems reasonable to assume that a military success of some importance had been won in his name in Britain. Coincidentally, perhaps, this could be the period in which any remaining Roman presence in the south-western territory of the Dumnonii is withdrawn.

286 - 287

Carausius, a northern Gaulish Roman commander of low birth who had been impressive under Maximianus' command, is suspected of collusion with raiding barbarians. When his execution is ordered he proclaims himself emperor and seizes the Diocese of the Britains. It is at this time that at least one of the Saxon Shore forts is built, that of Anderitum in the territory of the Regninses.

286 - 293

Marcus Mausaeus Carausius

Usurper emperor of Rome. Governed Britain. Murdered.


Following the loss of their territories in Gaul to Constantius Chlorus, the western Roman Caesar, Allectus assassinates Carausius and assumes command himself. Having been the finance minister for the empire of Britain, Allectus remains in power for three years until Rome is able to send Julius Asclepiodotus to deal with him.

Coin issued under Carausius
Shown here are two sides of a coin which was issued during the reign as emperor of Britannia of Carausius, forced to rebel in the face of charges of colluding with pirates

293 - 296

Caius Allectus

Usurper emperor of Rome. Killed.


Allectus is defeated and killed as Rome recaptures Britain, leaving its victorious commander in charge. Geoffrey of Monmouth gives Julius Asclepiodotus the title 'Duke of Cornwall'.

296 - 305


Roman commander who recovered Britain for Rome. Killed.


St George, an officer of the Roman army, is in Britain when he hears that Christians of the Roman Church are being persecuted by Emperor Diocletian in Rome. He returns to plead their case but is eventually beheaded for refusing to renounce his own belief (George becomes the patron saint of England in the fourteenth century).

fl c.305

Coel Godhebog

Lord of Colchester (early Roman capital of Britain). High king.


According to Geoffrey of Monmouth, Coel Godhebog is lord of Colchester, or 'Caer Colim' (effectively a dux, and perhaps even a protector of part of the Saxon Shore, given his location). In legendary terms, he begins a rebellion against Asclepiodotus and kills him in battle. Then Coel rules the country, submitting to Constantius (suggesting that Coel is a mere figurehead high king, just as Lucius may have been before him, in the second century). Coel dies after a short 'reign'.

305 - 306

Constantius Chlorus

Emperor of Rome. Married Helena. Died at Eboracum.

305 - 306

Britannia's two provinces are subdivided into four by Roman reorganisations. These are named (by no later than 314) as Britannia Prima (with a capital at Glevum in former Dobunni territory), Britannia Secunda, Maxima Caesariensis, and Flavia Caesariensis. The new provinces form part of the Diocese of the Britains. At the same time, Constantius personally leads a campaign into Caledonia to bring the elusive tribes in the Highlands to battle and ensure a period of renewed peace.

Sequential Maps of Roman Britain AD 43-425
Britannia's two provinces were subdivided into four by Emperor Constantius' reorganisations of AD 305-306 (click or tap on map to view full sized)

306 - 337

Constantine the Great

Emperor of Rome. Elevated at Eboracum.


Three bishops of the British Church participate in the Roman Church's Council of Arles: Eborius of York, Restitutus of London, and Adelphius of Lincoln or possibly Colchester.

337 - 343

The death of Constantine, and then his eldest son, Constantine II in battle in 340, proves serious for Britain. Its early fourth century age of peace and prosperity begins to vanish. Constans makes a sudden visit in early 343, suggesting that something happens in 342 to bring him to Britain at a most unusual time for Channel crossings (possibly warfare against the tribes north of Hadrian's Wall, as evidenced by severe fire damage to at least three forts: Risingham, High Rochester, and Bewcastle).

It is also suggested that the widespread refortification of cities which occurs in this century happens as a result of this visit. Units of Germanic laeti begin to appear in some cities, notably Venta Belgarum in the Belgae civitas, and migration begins from south-western Britain (notably the former territories of the Cornovii and Dumnonii) into Armorica.

Venta Belgarum
The Roman city of Venta Belgarum was refortified in the fourth century and Germanic mercenaries were brought in to improve the defences, suggesting an increasing lack of Roman soldiery fitted to the task


Following the rebellion of the Roman usurper Magnentius, a witch hunt is conducted, notably in the Diocese of the Britains, where the feared notarius (imperial notary) Paulus lives up to his reputation by targeting the innocent as well as the guilty.

In fact the methods used are so extreme and unjust that the vicarius of Britain, Flavius Martinus, attempts to persuade Paulus to release the innocent, and, failing, threatens resignation. This only results in false accusations against him, so as a final desperate act, Martinus is driven to attack Paulus with a sword. Unsuccessful, he commits suicide.

fl 356?

Carausius II

An unverified usurper between 354-358.


Three bishops of the British Church participate in the Roman Church's Council of Ariminum. The fact that they have to accept assistance with their travel suggests that as institutions the church organisation in Britain is not well-off.


According to Ammianus Marcellinus, the Picts, Scotti, Saxons, and Attacotti (possibly the Britons of Alt Clut) attack the Diocese of the Britains in what seems to be a serious incursion. The term 'Saxons' is used by the Romans to cover all Teutonic races, so these attacks may also be by Jutes, Frisians, or Angles on the eastern North Sea coast, or even the Danes from southern Scandinavia.

The traditional view of Picts as the 'painted people' is based on a description given by the Romans, and the use of blue woad as a body paint does seem to have been highly prevalent in the far north of Britain


Shortly before 367, three people are killed in Vindolanda Fort near Hadrian's Wall. Archaeologists discover two of them in the 1930s and a coroner's inquest decides they are 'victims of murder by persons unknown'. The third person, who is not necessarily killed at the same time, is thought to be a girl aged between eight and ten who may be tied up before she dies.

Human burials are strictly forbidden within built-up areas, and Vindolanda has a cemetery which has been laid out on the settlement's outskirts. The body is located in a shallow pit which is dug in a corner of the garrison's living quarters at the heart of the fort. It would be very difficult to get a body out of the barracks, through the wider fort and out of the gate, so hiding it here is much easier. Precise circumstances are unknown, however.


FeatureThe 'Barbarian Conspiracy' sees attacks falling on the Diocese of the Britains from all sides, although this seems to be the culmination of seven years of large-scale trouble on behalf of the Picts, Scotti, Saxons, and the mysterious Attacotti (see feature link).

The Rock of the Britons today
Dumbarton, the Rock of the Britons, probable home of the Attacotti, today is still a formbidable obstacle, although the defences of its British occupiers were finally breached in 870-871

Initially, Rome is taken by surprise, and the emperor's dux Fullofaudes is put out of action, either killed or cut off, probably near Hadrian's Wall. Then Nectaridus, comes maritimi tractus ('count of the maritime region'), is killed in action.

Both losses are serious blows, and the barbarians are now able to divide up into bands so that they can steal and sack and burn whatever they like. General Theodosius (the Elder) is sent to salvage the situation, which he does by restoring the army in Britain as a fighting force, pardoning soldiers who have deserted, attacking bands of brigands and looters wherever he finds them, and installing a new vicarius.

At the same point in time, the evidence points to Roman towns being much poorer, politically inactive, and socially weak, although by no means dead. However, decline is clearly setting in. Ratae, in the civitas of the Corieltavi, is struck by a serious fire which destroys the forum, basilica, and market hall, as well as a fair chunk of the centre of town. The buildings are never restored. Many forts along Hadrian's Wall and in the Pennines have also been damaged by fire, probably during the barbarian attack, and only some are restored.

London's Roman basicila
This model of the Second Great Forum and Basilica in Roman London is part of the Museum of London display on the city's Roman remains, which includes areas of surviving wall, both overground and (now) underground


In an act of imperial favour, an Alamannic king, Fraomar, is sent to Britain as a military tribune to command a Roman unit of Alemanni cavalry which is already stationed on the island in the modern county of Norfolk, as recorded by Ammianus. A German prince and his small army in Norfolk in the late fourth century sounds like a perfect avenue of entry for later waves of Angles in the following century, where they set up the kingdom of the East Engle.

Octavius / Octaf

Some confusion about this Octavius and Eudaf Hen of c.283.

Geoffrey of Monmouth relates that Octavius begins a rebellion against Roman rule which ousts the Roman proconsul. Then Octavius rules the country until Trahern, a Briton commanding Roman forces, defeats him in two battles and recovers the country for Rome.


Defeated Octavius for Rome. Murdered in the street.

Trahern is soon murdered however, and Octavius is restored to power. It is impossible to discover how true any of this might be. Perhaps it represents a level of unrest in the country which is related to the 'Barbarian Conspiracy' of 367, or perhaps it is simply an invention by later story tellers to enhance the background from which Magnus Maximus emerges.

fl c.378?

Octavius / Octaf

Regained power.

378 - 388

Magnus Maximus

Western Roman emperor 383-388.


FeatureAlthough his precise rank is unknown, Magnus Maximus (or Maximianus, British Maxsen, or Welsh Macsen Wledig - see feature link) is clearly a senior commander in Roman Britain, possibly with a position which is based in the west (possible, considering his influence on the region). In this year an invasion of Picts is successfully defeated by him shortly before he mounts his expedition into Gaul.

Magnus Maximus coin
The reverse of this coin issued by Magnus Maximus during his reign as co-emperor shows him standing, holding a laburnum and Victory on a globe

According to British oral tradition which later survives in Wales, High King Octaf has a daughter named Elen who is sought out by Emperor Maximus after he first sees her in a dream. Octaf's sister's son is Conan Meriadoc, the foremost of the princes of Britain. At first he is angry that a foreigner has been selected to marry Elen when there are so many eligible Britons, but after threatening to expel the foreigner by force he is won over and becomes firm friends with Magnus.


Maximus revolts against ineffectual governance from Rome and plans to invade Gaul with a large army. In preparation, he sets up defences in Wales to protect the west coast from Irish raiders. This includes the creation of a territory in mid-south Wales under the command of his son, Eugenius (incorporating Cernyw and Ewyas).

Another son is set up in Demetia in South Wales, while another, Constantine, is similarly set up as 'King of North Wales' (a title from later tradition). Some forts are abandoned at this time, probably as part of a general reorganisation of the available defensive units.

From this point on, all of Britain's 'high kings' originate from within the country, and Maximus selects Coel Hen as his replacement to command most of the militarised zone of 'Northern Britain'. Once the invasion of Gaul commences, Armorica is probably one of the first areas captured, and Maximus is credited by Geoffrey of Monmouth with setting up Conan Meriadoc as high king there.

Glomel in Brittany
The landscape of Armorica - extremely hilly inland with a wonderful, long coastline - would have seemed very familiar to the Britons who began to settle here from the late fourth century onwards (Glomel in the modern Côtes-d'Armor département is shown here)

383 - 388


Mentioned by Geoffrey of Monmouth. Ruled in Maximus' name.

c.384 - 390

Warfare flares up with the Picts again, and according to Gildas (the first of his 'Pictish Wars'), it lasts 'for many years'. Upon Maximus' death in 388, Rome's Emperor Theodosius sends a legion (or a specialist taskforce), probably by 390, to help stop the Pictish attacks once he has promises of submission from the island.


Another dux appears in Britain (the previous known incumbent of this military office being the unfortunate Fullofaudes who had been put out of action during the 'Barbarian Conspiracy' of 367). Coel Hen, as he is known in later British oral and written material, appears to exercise a good deal more power in the northern half of Britain than previous holders of the office.

FeatureAccording to tradition, he is assigned to the post by Magnus Maximus and, if this and other traditions about him are correct, then he may represent a transition between Roman military official and a ruler in an increasingly independent Britain (see feature link).

388? - 406?

Coel Hen

Dux Brittanorum. 'King of Northern Britain', based at Ebrauc.


The Deceangli and Ordovices tribes do not have a chance to re-emerge at a time in which Roman central authority in the west of Britain is fading earlier and faster than elsewhere.

Multangular Tower
The third century Multangular Tower in York (Ebrauc) lies at the western corner of the legionary fortress, which was probably the military HQ of fifth century Northern Britain. The tower's remains are now part of York's Museum Gardens

Under threat by waves of Irish raiders, much of the land of these two tribes is incorporated into a new territory when Cunedda Wledig and his branch of Romanised Venicones are transferred from the Manau dependency of the Guotodin to secure North Wales from the raiders. They are extremely successful, and the kingdom of Venedotia is formed by them.

392 - 394

Britain is again isolated from Rome by the revolt of Arbogast and Eugenius. Theodosius responds by raising his own two year-old son, Honorius, as Western Emperor, and marches on Italy, defeating his enemies at the Battle of Frigidus in 394 on the modern Italy-Slovenia border.


FeatureIt is possible that Roman forces defeat Saxons, Irish Scots, and the Picts in fighting which has been linked to the second of Gildas' 'Pictish Wars'. This is the probable source of the Britons' appeal for help to Rome around this time, although it seems possible that there is in fact no victory, and Stilicho merely attends to the island's defences before withdrawing more troops. One of the Saxon Shore forts known to undergo repairs at this time is that of Anderitum, in the civitas of the Regninses.


The official import of new coinage in large quantities comes to an end. Without those coins, trade as it has been known across the empire begins to stutter and slowly die out.

Magnus Maximus coin
Two sides of a coin issued in Britain under the command of Magnus Maximus, which would have remained in circulation until at least the second decade of the fifth century


Troops are withdrawn from Britain to form part of the Roman army which defeats a force of Goths and other barbarians in northern Italy. This comes in the same year as further Irish Scotti raids take place on the south coast.


The British provinces are relatively isolated and now constantly lack support from the Rome in their fight against barbarian incursions. In reaction to this, from 406 the remaining soldiers in Britain raise a series of their own claimants to the throne. Marcus is probably Geoffrey of Monmouth's Dionotus, whom he calls the duke of Cornwall. Gracianus Municeps is named by Bede.


Marcus (Dionotus?)

Elevated Roman soldier. Ruled for a few months.


Gracianus Municeps (Gratian)

Urban magistratus or councillor. Ruled for four months. Killed.

After failing to win support from Rome in their hour of need, Geoffrey of Monmouth's semi-mythical history of Britain has the Britons seeking help from Aldroenus, fourth king after Conanus in 'Little Britain, called at that time Armorica or Letavia'.

Guithelinus, archbishop of London (see the British Church entry for c.446), is sent to ask the king to take the crown of Britain, but the country has fallen so far from its former magnificence that he declines the offer. Instead he sends his brother, Constantine, with two thousand soldiers. Constantine is raised to the kingship of Britain.

Roman silver ingots
Silver ingots from the late fourth or early fifth century which were used to pay soldiers and civil servants in the Late Empire, and which were discovered at the site of the Tower of London, and at Reculver and Richborough in Kent

407 - 411

Constantine III (Custennin ap Selyf)

Usurper Western Roman emperor.

407 - 408

Not content with governing Britain, Constantine has his eye on the imperial purple. With Honorius weak in Italy, he quickly crosses into Gaul and secures the Rhine, making Arles, the recently relocated headquarters of the Gallic prefecture, his capital in 408.

408 - 411

Constans ap Custennin

Son. Caesar. Killed in Gaul.


Constantine sends his son, Constans, and General Gerontius to Hispania to defeat the cousins of Roman Emperor Honorius there and secure that province (Gerontius could be the Gerenton mentioned in connection with Domnonia in the Vannetais).

Stilicho's forces in Italy rebel and he is executed. As a result of this and intrigues at the imperial court, plus the fact that Alaric's Visigothic army is roaming Etruria, Honorius is left powerless, and gladly accepts Constantine as co-emperor.


The Alani, Suevi and Vandali enter Hispania, disrupting Constantine's hold on his territory. Gerontius rebels against Constantine, and raises Maximus as his own puppet emperor. With Constantine now in serious difficulties in Gaul, further Saxon raids convince the British and Armoricans to rebel and expel Roman officials entirely, thereby breaking ties with Rome which are never renewed.

Crossing the Rhine
The main bodies of the Vandali, Alani, and Suevi tribes crossed the Rhine at the end of 406, resulting in panic and chaos within the Roman empire

The Roman presence in Britain has been dwindling anyway, for at least the previous three decades, so the split probably produces little change, except that fully British officials now occupy former imperial posts. Records from this point become extremely sparse and native control on a national level of Post-Roman Britain appears to break down for a time.

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