A Brief History of Roman Britain

By Edorix

This article explores the history of Roman Britain, from Caesar’s first invasion and Claudius’ conquest, until the end of centralised Roman administration. This is the tale of Roman Britain, with all the famous episodes straightened out and in their proper place.

The place to start, as usual with Britain, is Julius Caesar, the first Roman to invade Britain with an army. I will not go into detail here – more information can be found here – but will simply take a brief look at his two expeditions.

In 55 BC, Caesar crossed the Channel to Britain with two legions. He was resisted on the coast by the Cantiaci tribe, but he drove them back and managed to secure a foothold. After winning a couple of skirmishes, he returned to Gaul after just three weeks.

The next year he was back, this time with five legions and two thousand cavalry. The Briton tribes rallied around Cassivellaunos, king of the tribe which would later be known as the Catuvellauni, and resisted Caesar’s advance with quick chariot ambushes and rapid retreats, but these had little effect. Meanwhile, the Trinovantes under prince Mandubracios allied with Caesar, who then laid siege to Cassivellaunos’s stronghold; this may have been the hillfort of Weathampstead, not far north of later Verulamium. According to Caesar, Cassivellaunos’s men were unable to resist the legions for long, and abandoned the fort; Cassivellaunos then sued for peace. After accepting his surrender, and that of five other tribes, he returned to Gaul. (The five tribes Caesar mentions are the Ancalites, Bibroci, Cassi, Cenimagni, and Segontiaci. The Cassi may have been Cassivellaunos’s own tribe, possibly the earlier name for the Catuvellauni; the other names probably all belong to Kent, where archaeology is able to discern four distinct polities.)

Occupied with their own affairs, the Romans did not return to Britain for a century. After a farcical near-invasion under the crazy Caligula in AD 40 – he ordered his men to line up on the beach and then told them to pick up all the sea-shells lying around as spoils of war – another invasion was finally organised under Claudius. Four legions, under general Aulus Plautius, assembled in Belgica, and, after a near mutiny by the scared troops (who were not very optimistic about invading mysterious islands inhabited by monsters off the edge of the map), crossed the Channel to Britain. Once more, the Catuvellauni led the resistance under their new leaders Caratacos and his brother Togodumnos. They fought two battles against the Romans, first at the River Medway and then at the Thames, but both times were soundly defeated. Togodumnos died of his wounds shortly after the Battle of the Thames, so Caratacos fled west to the Silures and the whole Southeast fell under Roman rule. Antedios and Cogidubnos remained kings of their tribal kingdoms – respectively, the Iceni and the Atrebates – but the rest was turned into a province, and the capital established at Camulodunum, ex-stronghold of the Trinovantes. Claudius himself traveled to Britain, accepted the surrender of tribal chiefs, and then returned to Rome for his triumph after just two weeks on the island.

Caratacos, however, was still at large in the West, in the territory of the Silures. So in AD 47, a new governor was sent to Britain, Publius Ostorius Scapula. He consolidated all the territory as far as the Trisantona (Trent) and Sabrina (Severn), and defeated a minor rebellion of the Iceni. Then he established a fortress on the Severn and invaded the territory of the Silures.

He defeated Caratacos in battle, but Caratacos then joined the Ordovices further North and continued to lead the resistance until AD 51. Finding no refuge from Scapula, he eventually ended up at the court of Cartimandua, queen of the Brigantes. He should have known that Cartimandua owed her position to the Romans; they had helped her oust her husband in order to gain the throne in exchange for her support. Caratacos greatly underestimated her loyalty to Rome, and he was handed over to Scapula in chains. He was taken to Rome, but convinced the emperor to spare his life, and lived out its remainder in the Eternal City.

The Silures continued to resist; Scapula died in AD 52, and was replaced by Aulus Didius Gallus, who continued to fight them but on the defensive, and also defeated an enemy insurgence into Brigantian territory. In AD 57, the province was stable. The Romans weren’t going anywhere.

Gallus was succeeded by one Quintus Veranius, who resumed a more aggressive policy against the Silures, but died in AD 59. He was replaced in AD 60 by Gaius Suetonius Paulinus, who at once prepared to invade the Druid sanctuary of Mona to break the back of the Briton resistance. A more detailed account of Boudicca’s rebellion, which at this point erupted, can be found here, so I will be brief. In AD 61, while Paulinus was busy in Wales, Boudicca of the Iceni rose up against the Romans and incited many other nearby tribes to revolt, such that Tacitus calls it “a revolt of the whole island”. After destroying the colony at Camulodunum, she then proceeded to sack Londinium and Verulamium. Paulinus, when he got wind of the rebellion, quickly reduced Mona and then force-marched to meet Boudicca. Greatly outnumbered, nonetheless he defeated her at the Battle of Watling Street. Boudicca committed suicide; but the rebellion was not yet over.

In AD 62, Paulinus, who it was feared would be too stern to treat the rebellious Britons with leniency, was replaced by Petronius Turpilianus. He pacified the province again, but did not risk foreign annexation. He was succeeded by Trebellius Maximus, and then Vettius Bolanus. The peaceful policy established by Turpilianus was continued until AD 71, when Petilius Cerealis took over. We have no reliable documented details, but over the course of his governorship the Brigantes were conquered and incorporated within the province; a great achievement, as the Brigantes were the most populous tribe on the island. In AD 75, he was replaced by Julius Frontinus, an equally great general, who at last managed to conquer the Silures and the other tribes of Wales.

In AD 78, Gnaeus Julius Agricola became the new governor. He defeated the Ordovices and reconquered Mona in his first year of office, and in the second consolidated the Northern part of the province by establishing numerous forts and garrisons. In AD 80 he penetrated the lands of the Maeatae, a confederation of tribes living North of the Brigantes but South of the Caledonii, and continued to consolidate them for the next two years. In AD 82 he contemplated an invasion of Hibernia, but did not carry it out.

In AD 83 he invaded Caledonia and defeated the Caledonii who tried to storm one of his camps. Marching north, in AD 84 he met the united tribes of Caledonia in battle at Mons Graupius. He had about fifteen thousand men; the Caledonians had over thirty thousand. The result was a great victory for Rome. The same year however, Domitian, jealous of his success, had him recalled. His gains to the North of the future line of Hadrian’s Wall – in AD 79 Agricola had a road built there, linking Luguvalium and Coria, which we know today as the Stanegate – were abandoned.

For the next few years of the occupation our documentation is scarcer, for Tacitus’ Annals end in AD 66 and his Agricola covers the rest until AD 84; but it seems little of note occurred. It is possible that some small-scale invasion of Ireland was attempted in this period; if so, nothing much came of it (except in modern times, when there was a great deal of excitement about an excavation of a suggested Roman camp at Drumanagh, near Dublin). In AD 100, Argiragos led the Brigantes in revolt, but was defeated. In AD 117, they rebelled again, and were again defeated. In AD 122, the emperor Hadrian visited Britain and, apparently more to keep the troops occupied and to awe the discontented Brigantes than for any other reason, ordered a giant stone wall to be built along the line of the Stanegate. It was completed in AD 138. Large sections of it still stand today.

Hadrian’s Wall; a mighty stone rampart stretching from coast to coast. A massive statement of power. The Romans were in charge; and they would remain so for another quarter millennium.

It was not, however, quite that simple. The reign of Antoninus Pius, Hadrian’s successor, saw the Roman border pushed up to the Forth-Clyde line again, under governor Lollius Urbicus, and Hadrian’s Wall abandoned. The Antonine Wall was built around 142, closing what is now the Southern Uplands into the Roman province. This ambition was, however, short-lived; the Brigantes revolted again in 155, and Governor Julius Verus had to vacate the wall to pacify them. He was back by 158, but the wall was abandoned with little ceremony within a decade: Northern Britannia was still inclined to snatch every opportunity for independence it found. The region between the walls was not entirely abandoned however: the main fortress at Trimontium, and several other small forts, were maintained until the year 180.

AD 180 marked something of a watershed, for in this year the Caledonians and the tribes of the Southern Uplands overran Hadrian’s Wall, killing the governor. Commodus despatched a new governor, Ulpius Marcellus, who swiftly made peace, but in 184 the troops mutinied.

This would not be the last time the garrison of Britain would mutiny against imperial authority. It was a long way from the imperial capital, and there was an exceedingly large army required to control the island – many governors of Britain might well fancy their chances. Commodus sent Pertinax to try to quell the revolt, but he was almost killed and fled back to Rome.

In 192 Commodus died and the empire was plunged into civil war for the first time in a hundred and twenty years; not least because of the ambitions of the new governor of Britain, Clodius Albinus, and Septimius Severus. The two originally conspired, but later fell out, and in 195 Clodius crossed to the continent with the British legions, where he was defeated by Severus. With the departure of the legions, Northern Britain was substantially weakened, and the tribes of the Southern Uplands and Lowlands, particularly a group known as the Maeatae, put serious pressure on the frontier and had to be bought off. In 208, this prompted Severus, who was now emperor, to follow in the footsteps of Agricola, embarking on a major invasion of Caledonia with a large force, to remind them who was in charge. He made dismal progress, and by 210 he had retreated to York, leaving the frontier back at Hadrian’s Wall. The Maeatae rebelled, and Severus dispatched his son Caracalla against them; but Severus died later that year, and both of his sons set their sights on the imperial purple instead.

The third century was a period of upheaval for much of the empire, and Britain was not exempt. The economic system it had developed was also failing. In 259-74 it was part of the breakaway Gallic empire of Postumus. Around 281, a Briton in the Roman army named Bonosus proclaimed himself emperor at Cologne on the Rhine, but was struck down after a protracted struggle by the real emperor Probus and took his own life.

In 286, Carausius, a Roman naval commander, declared an independent empire, taking over Britain and Northern Gaul, successfully fending off attempts at reconquest. In 293 several of his Gallic possessions were finally retaken, and Carausius was murdered, apparently by his treasurer, Allectus, who succeeded him briefly before an invasion by the emperor Constantius and Julius Asclepiodotus at last re-annexed Britain. Reforms under Constantius and Diocletian saw Britain divided into four provinces and an overall prefecture of the Galliae established, intended to limit the ability of Britain’s garrison to churn out emperors on a whim. Ironically, when Constantius died in York in 306, his son Constantine, the future Constantine the Great, successfully used the British garrison to take over the empire.

The early and mid fourth century saw a period of relative stability for Britain, with the economy gradually restructuring towards regional mass-production industries, bringing a measure of prosperity. However, Britain was increasingly coming under pressure from foes new and old: the Irish had begun to raid the Western coasts, the Caledonian Picts still periodically assaulted Hadrian’s Wall, and across the North Sea a fateful new threat was emerging. In the watershed year of 367, the garrison of Hadrian’s Wall rebelled, the Picts poured into Northern Britain, the Irish assailed from the West and the Saxons from the East in what is known as the barbarica conspiratio from which Britain never truly recovered: this was the first of the Anglo-Saxon invasions. In 383, another Roman commander who was based in Wales named Magnus Maximus, known as Macsen Wledig in high medieval Wales, dragged even more of Britain’s troops away to make his bid for the imperial throne. It has been suggested, based on much later sources, that some of his troops, unable to return to Britain, instead settled in Armorica, sowing the seeds of modern Brittany; there is, however, in fact no evidence for this, and the earliest settlement of Britons in Brittany may be no earlier than the later fifth century.

The end of Roman Britain is a matter of much dispute. By its nature, it is not covered by history, and the archaeology is in large part localised and difficult to draw generalisations from. Britain had been slowly de-urbanising since the third century, moving towards a system more based on small towns than major cities. Coinage may have been going out of use by the 370s, and there are no new issues after 407, the same year Constantine III withdrew even more troops from Britain to try and make himself emperor.

A letter of 410 by the emperor Honorius has traditionally been seen as the end date of Roman Britain; in fact there is no certainty that it was even addressed to the Britons. The more telling letter is one sent to Aetius in Gaul around the year 450, quoted by the sixth-century writer Gildas:

The barbarians drive us into the sea, the sea drives us back into the barbarians: between these two methods of death we are either slain or drowned.

Aetius may or may not have sent aid in the form of Germanus of Auxerre, who travelled to southern Britain and apparently fought against the Saxons. With retrospect, we know this was to little avail. Over the next two or three centuries, Romanness in Britain would be driven back to Wales, ever the least Roman part of the province, and there contained; and gradually what Romanness it had ever had faded. The rest of the province turned to the immigrant Anglo-Saxons for a new way of life to replace the old one that had failed; and what happened next is recounted elsewhere.