Julius Caesar first invaded with Britain with two legions during 55 BCE.
No one is sure why the Roman Empire invaded Britain. Celtic tribes of England may have supported the Gauls against the Roman forces of Julius Caesar during the Gallic War. The reason could have been economic. No one could dispute the mineral wealth of Britain with deposits of gold, silver, copper, lead and tin.
The Roman Legions first landed in Pegwell Bay near Dover in Kent. Caesar established a reconnaissance base and paved the way for a second invasion a year later in 54BCE when he returned with four legions. The Roman forces fought a number of skirmishes, laid siege to several tribal strongholds around Kent, and crossed the Thames.
Rather than occupying the new territory, Caesar returned to Gaul to crush a revolt and never returned. Caesar wanted spectacular military victories to bolster his political ambitions and the incursion into Britain became just a footnote in the Gallic war. A lasting consequence of the invasion was to install a Roman friendly Ruler, which developed into a series of client kingdoms where Rome won a new foothold in Britain not by boots on the ground but by trade, politics and diplomacy.
After Caesar's incursion relative peace ensued for about one hundred years but storm clouds were gathering as a new pretender to the Emperor's throne wanted a victory of his own. Claudius wanted to establish himself as Emperor but lacked military experience. By adding new provinces to the Empire, he could gain reputation. In 43 CE Claudius invaded Britain with four legions.
Claudius established a capital at Colchester and conquest of the island slowly continued over the next forty years. By 84 CE a network of forts, roads and towns consolidated Rome’s rule over the new province of Britannia.
By 70 CE the Romans had pushed into Scotland as far as Perth and built a defensive line called the Gask Ridge.
The Romans called the area north of Britain Caledonia and met fierce resistance from the Caledonian tribes known as the Picts. Even after being defeated in a pitch battle at the Grampian Mountains the Caledonian tribes still raided the northern frontier.
To protect the province the Emperor Hadrian commanded for a wall to be built. The wall was built in 122 CE and stretched from coast to coast ending in Wallsend near Newcastle. The wall was supported by a defensive ditch, mile castles and forts. The wall was guarded by 9,000 soldiers who came from all corners of the empire such as Belgium, Syria and Iraq.
In AD 140 Emperor Antonius Pius ordered his legions to advance 100 miles into Caledonia and build another frontier called the Antonine Wall. The Antonine Wall connected the Firth of Clyde in the west to the Firth of Forth in the East. Constructed by Roman Governor Quintus Lollius Urbicas using manpower provided by the three Legions II, VI and XX.
The wall was abandoned after only twenty years and the frontier fell back to Hadrian’s Wall in 160 CE.
No one is sure why the Antonine wall was abandoned. Maybe the frontier was closer to enemy lines and was attached more or that troops were needed elsewhere in the empire.
Mausaeus Carausius was a sailor who rose through the ranks in the British fleet and became Admiral.
The Romans suspected Carausius of corruption and embezzling treasure captured from Pirates that preyed on the coasts of Amorica and Belgica.
The Western Roman Emperor Maximaian ordered Carausius to report to Rome and face justice and possible execution.
With the support of his fleet and four legions garrisoned in Britain and Northern Gaul, Carausius rebelled and seized control of Britain declaring himself the third Emperor or the Emperor of the North in 286 CE.
Maximaian retaliated in in 288 but his forces were defeated owing to bad weather and the military skill of Carausius.
Britain enjoyed a period of independence, where the Picts in the North where driven back behind Hadrian’s Wall and a series of coastal forts were built along the Saxon Shore.
Anglo Saxon mercenaries bolstered defences and supported the four legions and fleet.
In 293 CE Romans attacked rebel forces holding the port of Boulogne. Sensing weakness the British Chancellor Allectus assassinated Carausius and took control over Britain. Allectus was only to rule for three years until he was defeated and killed when Rome invaded and retook the province in 296.
In 367 CE the Franks, Anglo-Saxons, Picts and Attacotti joined forces and breached Hadrian’s Wall. They were defeated by Roman forces during a year long war. The Roman forces in Britain included an up and coming soldier called Magnus Maximus.
Maximus was Roman general assigned to Britain in 380 to defeat invading Scots and Picts.
Ambitious for imperial power and with a distinguished military career his troops proclaimed Maximus Emperor.
In 383 CE Maximus marched into Gaul to take on the Western Emperor Gratian taking with him most of Britain’s military forces.
After defeating Gratian the Eastern emperor Theodosius I intervened and proclaimed Maximus Emperor of Britain and Gaul and Valentinian II ruler of Italy, Spain and Africa.
In 387 Maximus invaded Italy and Emperor Valentinian fled. Theodosius intervened and defeated then executed Maximus in 388.
The unpaid Legions in Britain revolted in 406 CE. The army chose a rapid succession of two leaders who were promptly disposed. An ordinary soldier called Flavius Claudius Constantine became emperor of Britain in 407.
Like Maximus before he marched into Gaul and in doing so depleted Britain of its garrisons.
In December, that year invading Vandals crossed the Rhine and overwhelmed Roman defenses. Constantine fought a successful campaign against the invaders and controlled all of Gaul. Constantine III became co-emperor with Honorius in 409.
The Vandal tribes attacked Gaul and defeated Constantine’s forces in Gaul and those who defended the Rhine.
Cut off and feeling betrayed Britain revolted against Constantine III and expelled his Roman officials.
Weakened by internal conflict Rome had become vulnerable to attack by the Visigoths.
When Britain asked Emperor Honorius for military help in 410, it was too late as Visigoths were sacking the city of Rome.
Map showing Roman Roads and Major Roman Towns.
Hover over the towns for more information.
The black lines on the map represent Hadrians Wall and the Antonine Wall.