Roman Britain was the territory that became the Roman province of Britannia after the Roman conquest of Britain, consisting of a large part of the island of Great Britain. The occupation lasted from AD43 to AD410.
Britain was invaded by Julius Caesar in 55 and 54BC as part of the Gallic Wars. According to Caesar, the Britons had been overrun or culturally assimilated by the Belgae during the British Iron Age and had been aiding Caesar's enemies. The Belgae were the only Celtic tribe to cross the sea into Britain, for to all other Celtic tribes this land was unknown. Caesar received tribute, installed the Celtic king Mandubracius over the Trinovantes, and returned to Gaul. Planned invasions under Augustus were called off in 34, 27, and 25 BC. In AD 40 , Caligula assembled 200,000 men at the Channel on the continent, only to have them gather seashells () according to Suetonius, perhaps as a symbolic gesture to proclaim Caligula's victory over the sea. Three years later, Claudius directed four legions to invade Britain and restore the exiled king Verica over the Atrebates. The Romans defeated the Catuvellauni, and then organized their conquests as the province of Britain. By AD 47, the Romans held the lands southeast of the Fosse Way. Control over Wales was delayed by reverses and the effects of Boudica's uprising, but the Romans expanded steadily northwards.
The conquest of Britain continued under command of Gnaeus Julius Agricola (77–84), who expanded the Roman Empire as far as Caledonia. In mid-84, Agricola faced the armies of the Caledonians, led by Calgacus, at the Battle of Mons Graupius. Battle casualties were estimated by Tacitus to be upwards of 10,000 on the Caledonian side and about 360 on the Roman side. The bloodbath at Mons Graupius concluded the forty-year conquest of Britain, a period that possibly saw between 100,000 and 250,000 Britons killed. In the context of pre-industrial warfare and of a total population of Britain of , these are very high figures.
Under the 2nd-century emperors Hadrian and Antoninus Pius, two walls were built to defend the Roman province from the Caledonians, Hadrian’s Wall and the Antonine Wall, the first of stone and the second largely of turf. The first is the better preserved. Around AD 197, the Severan Reforms divided Britain into two provinces: Britannia Superior and Britannia Inferior. In the early fourth century, Britannia was divided into four provinces under the direction of a vicarius, who administered the , and who was himself under the overall authority of the praetorian prefecture of the Gallic region, based at Trier. A fifth province, Valentia, is attested in the later 4th century. For much of the later period of the Roman occupation, Britannia was subject to barbarian invasions and often came under the control of imperial usurpers and imperial pretenders. The final Roman withdrawal from Britain occurred around 410; the native kingdoms are considered to have formed Sub-Roman Britain after that.
Following the conquest of the Britons, a distinctive Romano-British culture emerged as the Romans introduced improved agriculture, urban planning, industrial production, and architecture. The Roman goddess Britannia became the female personification of Britain. After the initial invasions, Roman historians generally only mention Britain in passing. Thus, most present knowledge derives from archaeological investigations and occasional epigraphic evidence lauding the Britannic achievements of an emperor. Roman citizens settled in Britain from many parts of the Empire.
History
Early contact
Britain was known to the Classical world. The Greeks, the Phoenicians and the Carthaginians traded for Cornish tin in the 4th century BC. The Greeks referred to the ', or "tin islands", and placed them near the west coast of Europe. The Carthaginian sailor Himilco is said to have visited the island in the 6th or 5th century BC and the Greek explorer Pytheas in the 4th. It was regarded as a place of mystery, with some writers refusing to believe it existed.
The first direct Roman contact was when Julius Caesar undertook two expeditions in 55 and 54 BC, as part of his conquest of Gaul, believing the Britons were helping the Gallic resistance. The first expedition was more a reconnaissance than a full invasion and gained a foothold on the coast of Kent but was unable to advance further because of storm damage to the ships and a lack of cavalry. Despite the military failure, it was a political success, with the Roman Senate declaring a 20-day public holiday in Rome to honour the unprecedented achievement of obtaining hostages from Britain and defeating Belgic tribes on returning to the continent.
The second invasion involved a substantially larger force and Caesar coerced or invited many of the native Celtic tribes to pay tribute and give hostages in return for peace. A friendly local king, Mandubracius, was installed, and his rival, Cassivellaunus, was brought to terms. Hostages were taken, but historians disagree over whether any tribute was paid after Caesar returned to Gaul.
Caesar conquered no territory and left no troops behind, but he established clients and brought Britain into Rome's sphere of influence. Augustus planned invasions in 34, 27 and 25 BC, but circumstances were never favourable, and the relationship between Britain and Rome settled into one of diplomacy and trade. Strabo, writing late in Augustus's reign, claimed that taxes on trade brought in more annual revenue than any conquest could. Archaeology shows that there was an increase in imported luxury goods in southeastern Britain. Strabo also mentions British kings who sent embassies to Augustus, and Augustus's own ' refers to two British kings he received as refugees. When some of Tiberius's ships were carried to Britain in a storm during his campaigns in Germany in 16 AD, they came back with tales of monsters.
Rome appears to have encouraged a balance of power in southern Britain, supporting two powerful kingdoms: the Catuvellauni, ruled by the descendants of Tasciovanus, and the Atrebates, ruled by the descendants of Commius. This policy was followed until AD 39 or 40, when Caligula received an exiled member of the Catuvellaunian dynasty and planned an invasion of Britain that collapsed in farcical circumstances before it left Gaul. When Claudius successfully invaded in AD 43, it was in aid of another fugitive British ruler, Verica of the Atrebates.
Roman invasion
thumb|upright=1.3|Conquests under [[Aulus Plautius, focused on the commercially valuable southeast of Britain]]
The invasion force in AD 43 was led by Aulus Plautius, but it is unclear how many legions were sent. The ', commanded by future emperor Vespasian, was the only one directly attested to have taken part. The ', the ' (later styled ') and the ' (later styled ') are known to have served during the Boudican revolt of 60/61, and were probably there since the initial invasion. This is not certain because the Roman army was flexible, with units being moved around whenever necessary. The ' may have been permanently stationed, with records showing it at Eboracum (York) in 71 and on a building inscription there dated 108, before being destroyed in the east of the Empire, possibly during the Bar Kokhba revolt.
The invasion was delayed by a troop mutiny until an imperial freedman persuaded them to overcome their fear of crossing the Ocean and campaigning beyond the limits of the known world. They sailed in three divisions, and probably landed at Richborough in Kent; at least part of the force may have landed near Fishbourne, West Sussex.
The Catuvellauni and their allies were defeated in two battles: the first, assuming a Richborough landing, on the river Medway, the second on the river Thames. One of their leaders, Togodumnus, was killed, but his brother Caratacus survived to continue resistance elsewhere. Plautius halted at the Thames and sent for Claudius, who arrived with reinforcements, including artillery and elephants, for the final march to the Catuvellaunian capital, Camulodunum (Colchester). Vespasian subdued the southwest, Cogidubnus was set up as a friendly king of several territories, and treaties were made with tribes outside direct Roman control.
Establishment of Roman rule
After capturing the south of the island, the Romans turned their attention to what is now Wales. The Silures, Ordovices and Deceangli remained implacably opposed to the invaders and for the first few decades were the focus of Roman military attention, despite occasional minor revolts among Roman allies like the Brigantes and the Iceni. The Silures were led by Caratacus, and he carried out an effective guerrilla campaign against Governor Publius Ostorius Scapula.
In 51, Ostorius lured Caratacus into a set-piece battle and defeated him. The British leader sought refuge among the Brigantes, but their queen, Cartimandua, proved her loyalty by surrendering him to the Romans. He was brought as a captive to Rome, where a dignified speech he made during Claudius's triumph persuaded the emperor to spare his life. The Silures were still not pacified, and Cartimandua's ex-husband Venutius replaced Caratacus as the most prominent leader of British resistance.
Paulinus rode to London (then called Londinium), the rebels' next target, but concluded it could not be defended. Abandoned, it was destroyed, as was Verulamium (St. Albans). Between seventy and eighty thousand people are said to have been killed in the three cities. But Paulinus regrouped with two of the three legions still available to him, chose a battlefield, and, despite being outnumbered by more than twenty to one, defeated the rebels in the Battle of Watling Street. Boudica died not long afterwards, by self-administered poison or by illness.
thumb|[[Templeborough|Templeborough Roman fort in South Yorkshire. The reconstruction was created for Rotherham Museums and Galleries.]]
There was further turmoil in 69, the "Year of the Four Emperors". As civil war raged in Rome, weak governors were unable to control the legions in Britain, and Venutius of the Brigantes seized his chance. The Romans had previously defended Cartimandua against him, but this time were unable to do so. Cartimandua was evacuated, and Venutius was left in control of the north of the country. After Vespasian secured the empire, his first two appointments as governor, Quintus Petillius Cerialis and Sextus Julius Frontinus, took on the task of subduing the Brigantes and Silures respectively. Frontinus extended Roman rule to all of South Wales, and initiated exploitation of the mineral resources, such as the gold mines at Dolaucothi.
In the following years, the Romans conquered more of the island, increasing the size of Roman Britain. Governor Gnaeus Julius Agricola, father-in-law to the historian Tacitus, conquered the Ordovices in 78. With the ' legion, Agricola defeated the Caledonians in 84 at the Battle of Mons Graupius, in north-east Scotland. This was the high-water mark of Roman territory in Britain: shortly after his victory, Agricola was recalled from Britain back to Rome and awarded the ornaments of a triumph, before returning to continue as governor. By 87 the decision was taken to abandon most of the land north of the Cheviot Hills allowing for troops to be moved to other frontiers which were under pressure. Tacitus reports Agricola as feeling bitter about this turn of events.
For much of the history of Roman Britain, a large number of soldiers were garrisoned on the island. This required that the emperor station a trusted senior man as governor of the province. As a result, many future emperors served as governors or legates in this province, including Vespasian, Pertinax, and Gordian I.
Occupation of and retreat from southern Scotland
There is no historical source describing the decades that followed Agricola's recall. Even the name of his replacement is unknown. Archaeology has shown that some Roman forts south of the Forth–Clyde isthmus were rebuilt and enlarged; others appear to have been abandoned. By 87 the frontier had been consolidated on the Stanegate. Roman coins and pottery have been found circulating at native settlement sites in the Scottish Lowlands in the years before 100, indicating growing Romanisation. Some of the most important sources for this era are the writing tablets from the fort at Vindolanda in Northumberland, mostly dating to 90–110. These tablets provide evidence for the operation of a Roman fort at the edge of the Roman Empire, where officers' wives maintained polite society while merchants, hauliers and military personnel kept the fort operational and supplied.
Around 105 there appears to have been a serious setback at the hands of the tribes of the Picts: several Roman forts were destroyed by fire, with human remains and damaged armour at Trimontium (at modern Newstead, in SE Scotland) indicating hostilities at least at that site. There is also circumstantial evidence that auxiliary reinforcements were sent from Germany, and an unnamed British war of the period is mentioned on the gravestone of a tribune of Cyrene. Trajan's Dacian Wars may have led to troop reductions in the area or even total withdrawal followed by slighting of the forts by the Picts rather than an unrecorded military defeat. The Romans were also in the habit of destroying their own forts during an orderly withdrawal, in order to deny resources to an enemy. In either case, the frontier probably moved south to the line of the Stanegate at the Solway–Tyne isthmus around this time.
thumb|upright=1.2|left|[[Hadrian's Wall viewed looking east from Housesteads Roman Fort (Vercovicium). The wall in the background has been consolidated.]]
thumb|upright=1.5|left|Prima Europe tabula. A 1486 [[woodcut copy of Ptolemy's 2nd-century map of Roman Britain]]
A new crisis occurred at the beginning of Hadrian's reign (117): a rising in the north which was suppressed by Quintus Pompeius Falco. When Hadrian reached Britannia on his famous tour of the Roman provinces around 120, he directed an extensive defensive wall, known to posterity as Hadrian's Wall, to be built close to the line of the Stanegate frontier. Hadrian appointed Aulus Platorius Nepos as governor to undertake this work who brought the ' legion with him from '. This replaced the famous ', whose disappearance has been much discussed. Archaeology indicates considerable political instability in Scotland during the first half of the 2nd century, and the shifting frontier at this time should be seen in this context.
In the reign of Antoninus Pius (138–161) the Hadrianic border was briefly extended north to the Forth–Clyde isthmus, where the Antonine Wall was built around 142 following the military reoccupation of the Scottish lowlands by a new governor, Quintus Lollius Urbicus.
The first Antonine occupation of Scotland ended as a result of a further crisis in 155–157, when the Brigantes revolted. With limited options to despatch reinforcements, the Romans moved their troops south, and this rising was suppressed by Governor Gnaeus Julius Verus. Within a year the Antonine Wall was recaptured, but by 163 or 164 it was abandoned. The second occupation was probably connected with Antoninus's undertakings to protect the Votadini or his pride in enlarging the empire, since the retreat to the Hadrianic frontier occurred not long after his death when a more objective strategic assessment of the benefits of the Antonine Wall could be made. The Romans did not entirely withdraw from Scotland at this time: the large fort at Newstead was maintained along with seven smaller outposts until at least 180.
During the twenty-year period following the reversion of the frontier to Hadrian's Wall in 163/4, Rome was concerned with continental issues, primarily problems in the Danubian provinces. Increasing numbers of hoards of buried coins in Britain at this time indicate that peace was not entirely achieved. Sufficient Roman silver has been found in Scotland to suggest more than ordinary trade, and it is likely that the Romans were reinforcing treaty agreements by paying tribute to their implacable enemies, the Picts.
Under Marcus Aurelius, in 175, an army of Sarmatian cavalry, consisting of 5,500 men, arrived in Britannia. In 180, Hadrian's Wall was breached by the Picts and the commanding officer or governor was killed there in what Cassius Dio described as the most serious war of the reign of Commodus. Ulpius Marcellus was sent as replacement governor and by 184 he had won a new peace, only to be faced with a mutiny from his own troops. Unhappy with Marcellus's strictness, they tried to elect a legate named Priscus as usurper governor; he refused, but Marcellus was lucky to leave the province alive. The Roman army in Britannia continued its insubordination: they sent a delegation of 1,500 to Rome to demand the execution of Tigidius Perennis, a Praetorian prefect who they felt had earlier wronged them by posting lowly equites to legate ranks in Britannia. Commodus met the party outside Rome and agreed to have Perennis killed, but this only made them feel more secure in their mutiny.
The future emperor Pertinax (lived 126–193) was sent to Britannia to quell the mutiny and was initially successful in regaining control, but a riot broke out among the troops. Pertinax was attacked and left for dead, and asked to be recalled to Rome, where he briefly succeeded Commodus as emperor in 192.
Third century
The death of Commodus put into motion a series of events which eventually led to civil war. Following the short reign of Pertinax, several rivals for the emperorship emerged, including Septimius Severus and Clodius Albinus. The latter was the new governor of Britannia, and had seemingly won the natives over after their earlier rebellions; he also controlled three legions, making him a potentially significant claimant. His sometime rival Severus promised him the title of Caesar in return for Albinus's support against Pescennius Niger in the east. Once Niger was neutralised, Severus turned on his ally in Britannia; it is likely that Albinus saw he would be the next target and was already preparing for war.
Albinus crossed to Gaul in 195, where the provinces were also sympathetic to him, and set up at Lugdunum. Severus arrived in February 196, and the ensuing battle was decisive. Albinus came close to victory, but Severus's reinforcements won the day, and the British governor committed suicide. Severus soon purged Albinus's sympathisers and perhaps confiscated large tracts of land in Britain as punishment. Albinus had demonstrated the major problem posed by Roman Britain. In order to maintain security, the province required the presence of three legions, but command of these forces provided an ideal power base for ambitious rivals. Deploying those legions elsewhere would strip the island of its garrison, leaving the province defenceless against uprisings by the native Celtic tribes and against invasion by the Picts and Scots.
The traditional view is that northern Britain descended into anarchy during Albinus's absence. Cassius Dio records that the new Governor, Virius Lupus, was obliged to buy peace from a fractious northern tribe known as the Maeatae. The succession of militarily distinguished governors who were subsequently appointed suggests that enemies of Rome were posing a difficult challenge, and Lucius Alfenus Senecio's report to Rome in 207 describes barbarians "rebelling, over-running the land, taking loot and creating destruction". In order to rebel, of course, one must be a subject – the Maeatae clearly did not consider themselves such. Senecio requested either reinforcements or an Imperial expedition, and Severus chose the latter, despite being 62 years old. Archaeological evidence shows that Senecio had been rebuilding the defences of Hadrian's Wall and the forts beyond it, and Severus's arrival in Britain prompted the enemy tribes to sue for peace immediately. The emperor had not come all that way to leave without a victory, and it is likely that he wished to provide his teenage sons Caracalla and Geta with first-hand experience of controlling a hostile barbarian land.
thumb|Northern campaigns, 208–211
An invasion of Caledonia led by Severus and probably numbering around 20,000 troops moved north in 208 or 209, crossing the Wall and passing through eastern Scotland on a route similar to that used by Agricola. Harried by punishing guerrilla raids by the northern tribes and slowed by an unforgiving terrain, Severus was unable to meet the Caledonians on a battlefield. The emperor's forces pushed north as far as the River Tay, but little appears to have been achieved by the invasion, as peace treaties were signed with the Caledonians. By 210 Severus had returned to York, and the frontier had once again become Hadrian's Wall. He assumed the title ' but the title meant little with regard to the unconquered north, which clearly remained outside the authority of the Empire. Almost immediately, another northern tribe, the Maeatae, went to war. Caracalla left with a punitive expedition, but by the following year his ailing father had died and he and his brother left the province to press their claim to the throne.
As one of his last acts, Severus tried to solve the problem of powerful and rebellious governors in Britain by dividing the province into ' and '. This kept the potential for rebellion in check for almost a century. Historical sources provide little information on the following decades, a period known as the Long Peace. Even so, the number of buried hoards found from this period rises, suggesting continuing unrest. A string of forts were built along the coast of southern Britain to control piracy; and over the following hundred years they increased in number, becoming the Saxon Shore Forts.
During the middle of the 3rd century, the Roman Empire was convulsed by barbarian invasions, rebellions and new imperial pretenders. Britannia apparently avoided these troubles, but increasing inflation had its economic effect. In 259 a so-called Gallic Empire was established when Postumus rebelled against Gallienus. Britannia was part of this until 274 when Aurelian reunited the empire.
Around the year 280, a half-British officer named Bonosus was in command of the Romans' Rhenish fleet when the Germans managed to burn it at anchor. To avoid punishment, he proclaimed himself emperor at Colonia Agrippina (Cologne) but was crushed by Marcus Aurelius Probus. Soon afterwards, an unnamed governor of one of the British provinces also attempted an uprising. Probus put it down by sending irregular troops of Vandals and Burgundians across the Channel.
The Carausian Revolt led to a short-lived Britannic Empire from 286 to 296. Carausius was a Menapian naval commander of the Britannic fleet; he revolted upon learning of a death sentence ordered by the emperor Maximian on charges of having abetted Frankish and Saxon pirates and having embezzled recovered treasure. He consolidated control over all the provinces of Britain and some of northern Gaul while Maximian dealt with other uprisings. An invasion in 288 failed to unseat him and an uneasy peace ensued, with Carausius issuing coins and inviting official recognition. In 293, the junior emperor Constantius Chlorus launched a second offensive, besieging the rebel port of Gesoriacum (Boulogne-sur-Mer) by land and sea. After it fell, Constantius attacked Carausius's other Gallic holdings and Frankish allies and Carausius was usurped by his treasurer, Allectus. Julius Asclepiodotus landed an invasion fleet near Southampton and defeated Allectus in a land battle.
Fourth-century government
right|upright=0.9|thumb|One possible arrangement of the late Roman provinces, with [[Valentia (Roman Britain)|Valentia between the walls]]
right|upright=0.9|thumb|Another possible arrangement, with other possible placements of [[Valentia (Roman province)|Valentia noted]]
In a reform carried out by 312, the Diocese of Britain was divided into four provinces, Maxima Caesariensis, Flavia Caesariensis, Britannia Prima and Britannia Secunda. The diocese was governed by a vicarius, and Britain was part of the Gallic region under the overall authority of a praetorian prefect, based at Trier.
The vicarius was based at Londinium as the principal city of the diocese. Londinium and Eboracum continued as provincial capitals and the territory was divided up into smaller provinces for administrative efficiency.
Civilian and military authority of a province was no longer exercised by one official, and the governor was stripped of military command, which was handed over to the Dux Britanniarum by 314. The governor of a province assumed more financial duties (the procurators of the Treasury ministry were slowly phased out in the first three decades of the 4th century). The Dux was commander of the troops of the Northern Region, primarily along Hadrian's Wall, and his responsibilities included protection of the frontier. He had significant autonomy due in part to the distance from his superiors.
The tasks of the vicarius were to control and coordinate the activities of governors; monitor but not interfere with the daily functioning of the Treasury and Crown Estates, which had their own administrative infrastructure; and act as the regional quartermaster-general of the armed forces. In short, as the sole civilian official with superior authority, he had general oversight of the administration, as well as direct control, while not absolute, over governors who were part of the prefecture; the other two fiscal departments were not.
The early-4th-century Verona List, the late-4th-century work of Sextus Rufus, and the early-5th-century List of Offices and work of Polemius Silvius all list four provinces by some variation of the names Britannia I, Britannia II, Maxima Caesariensis, and Flavia Caesariensis; all of these seem to have initially been directed by a governor (praeses) of equestrian rank. The 5th-century sources list a fifth province named Valentia and give its governor and Maxima's a consular rank. Ammianus mentions Valentia as well, describing its creation by Theodosius the Elder in 369 after the quelling of the Great Conspiracy. Ammianus considered it a re-creation of a formerly lost province, leading some to think there had been an earlier fifth province under another name (may be the enigmatic "Vespasiana"?), and leading others to place Valentia beyond Hadrian's Wall, in the territory abandoned south of the Antonine Wall.
Reconstructions of the provinces and provincial capitals during this period partially rely on ecclesiastical records. On the assumption that the early bishoprics mimicked the imperial hierarchy, scholars use the list of bishops for the 314 Council of Arles. The list is patently corrupt: the British delegation is given as including a Bishop "Eborius" of Eboracum and two bishops "from Londinium" (one ' and the other ').