Limes Britannicus

Despite a rapid victory over the tribes in the south, which Claudius' field commander, Aulus Plautius, achieved in 43 AD for Rome, the resistance of the British was not completely broken for a long time afterwards.

Behind the protection of Hadrian's Wall and that formed by the natural coastal boundaries to the east, south and west, the region we now know as England was heavily influenced by Roman civilisation.

Claudius had a low reputation among his troops and was forced - according to the tradition of emperors - to acquire glory on the battlefield in order to secure his rule permanently.

Coin missions dating to this time indicate that Britain was in a "permanent state of defence" and pre-Roman tribal societies continued to occupy the outer regions of the island.

Moreover, in the lands between these rivers and Hadrian's Wall, the Central Lowlands, there were still four other Celtic tribes - the Votadini, Selgovae, Damnonii and Novantae - which Rome sought to incorporate in order to be able to neutralise their fighting power and make use of their farmland.

At the end of the 2nd century seafaring Germanic peoples – the Angles, Saxons and Franks - began to threaten the Gallic and British coasts with the first raids from the continent.

Carausius used inter alia the anger of the Britons arising from their neglect by Rome for his own power-political purposes and founded his own empire consisting of Britain and a strip of land in northern Gaul.

Due to the precarious security situation in the rest of the Empire, units were increasingly withdrawn from the island so that, in the end, the British provinces were almost exclusively guarded by locally raised auxilia or newly recruited Germanic mercenaries.

He wanted to take advantage of the political and military chaos in Gaul caused by the barbarian invasion to strengthen his power and crossed with his loyal troops across the English Channel.

Around 410 AD, the last units of the mobile field army left the island, drawing to a close 300 years of Roman rule over Britain.

[5] Four years after the Roman invasion, the conquered territory extended roughly as far as a line from Exeter (Isca Dumnoniorum) to Lincoln (Lindum Colonia), an important intra-Britannic transport hub.

After his recall, Caledonia, with its harsh climate and sparse resources, was once again left to itself and the Romans restricted themselves to securing the most fertile and economically attractive regions of the island.

In 87 AD, when Domitian withdrew the Legio II Augusta and the majority of auxiliary units from the Scottish Lowlands for his Dacian war, this region could also no longer be held due to the lack of troops.

Unlike the other limites in the Roman Empire, there was no natural barrier such as wide river that crossed the entire island and whose banks could be relatively easily fortified against continuous attacks and plundering by the northern tribes.

[9] Defence and observation on the coasts in the West and Southeast were also carried out by chains of castra, watchtowers and signal towers and along the main roads in the interior.

At the end of his reign, in the early 3rd century, the already seriously ill Septimius Severus and his sons, Caracalla and Geta, led a costly campaign against the tribal areas north of the border.

In order to muster enough soldiers for their march on Rome, they reduced their British garrisons in every case far below the level needed for them to mount a credible defence.

In the early third century, the Legio II Augusta returned to Caerleon after a prolonged campaign; despite that, the number of Roman troops in Wales remained very low.

In the late third century, the local coastline was increasingly threatened by Irish and Scots bandits whose pirate ships operated mostly in the Bristol Channel, the seaway between the southwest peninsula of England and southern Wales.

In his chronicle of the second half of the 4th century Eutropius reported that the commander of the Classis Britannica, Carausius, was tasked in 285 with tackling Frankish and Saxon piracy in the English Channel.

The heavily branched river system in Britain enabled the Germanic invaders to quickly penetrate the interior of the island in their small flat boats.

During Carausius' short-lived Britannic Empire, these strategically important fortresses and naval stations were probably manned by his most loyal officers and soldiers, who could just as easily repel Roman invaders.

In 368, army commander, count Theodosius, landed in Britannia where, on behalf of Emperor Valentinian I, he first of all overthrew the insurrection by Valentinus, then defeated a "barbarian conspiracy" of Picts, Scots and Anglo-Saxons and finally secured Hadrian's Wall again.

However, a decisive factor was probably that the Roman troops on the island, who were involved in constant and costly minor wars with the Picts, Scots and Irish, felt that the Emperor had left them in the lurch.

Before leaving Britain, Magnus Maximus probably appointed a certain Coelius as the supreme commander on the northern border; he was the last to use the title Dux Britanniarum ("Duke of Britannia") introduced by the Romans.

However, the administrative districts of the late Roman provinces in the south quickly became small independent kingdoms by inheritance, which is why the dux soon ceased to receive any material or financial contributions from there.

As the pressure of Anglo-Saxon migration in Britain grew steadily and they slowly acquired land in the fertile lowlands, the Romano-British fled to the forts of the Saxon Shore, which were probably largely still intact.

[16] Because there was no central government in the south at that time, the local commanders conceded to the Irish their conquest of the Welsh coast and the remoter regions of Cornwall and Devon.

After the collapse of Roman administration in the early fifth century, the ancient tribal communities were revived and the West disintegrated rapidly into little, independent, constantly warring kingdoms.

Despite that, in 185 AD, 1,500 British lanciarii (javelin throwers) marched to the gates of Rome and murdered there the praetorian prefect of the Commodus, Tigidius Perennis, and his family.