By Claudius’s time, no foreign territory was deemed immune to conquest. The recently enthroned Claudius needed to consolidate his authority, and a massive invasion force was mustered under the command of Aulus Plautius. The Romans swept rapidly through south-east England, brutally eliminating whatever resistance they encountered, which wasn’t much. A tribal chieftain, Caratacus, retreating tactically from the early Roman capital Camulodunum (Colchester) to south Wales, managed to put up enough of a fight for the Romans to spare his life after he was captured and brought to Rome. There was also continued resistance in Wales, largely led by Druid priests.

After Caratacus, the next spirited fightback was a decade later, when the widowed tribal queen, Boudicca, spearheaded a combined rebel force of her own Iceni people and the neighbouring Trinovantes. They burned down three major southern towns, including the newly founded Londinium. When this coalition army was annihilated, Boudicca swallowed poison to avoid the indignity of capture.

During the decades of the 70s and 80s, the Romans extended their sway over the island, pushing north-westwards from their southern base. They caused panic and terror wherever they arrived, but their presence also led to the founding of many towns and cities, such as Bath, Lincoln, Chester and York, connected by long, straight roads like Watling Street and Fosse Way. The push eventually crossed into Scotland, but the further north the imperial forces penetrated, the less appetite they appeared to have for hanging on to the new territories won.

After a prolonged general withdrawal from the Scottish outposts, the emperor Hadrian ordered the construction of a defensive wall across the border in AD 122, from Carlisle to Newcastle. Although the wall was never finished, it marked the northern border of what was by then a continent-wide empire. In 138, Hadrian’s successor Antonius Pius ordered a new wall to be built across Scotland, pushing the boundary further north again, but in due course this too was abandoned, and the wall Hadrian had ordered once again became the British Rubicon.

The local nobility survived by reaching accommodations with Roman power. Wholesale Romanisation of local culture and customs was the price paid for a relatively peaceable coexistence with the occupying power. Despite the popular image, most ordinary people probably remained fairly untouched by the conquest. Life at the most primitive level continued unscathed, but by the third century, Britain was booming under Roman tutelage. Wool and grain, animal skins, and metals such as silver and tin, underpinned a flourishing export trade.

When the end came, Britain was far from being the ruthlessly oppressed colony suddenly breaking the chains of its bondage. It had established its own economic and political traditions within the Empire, even electing its own rulers, either from within the Roman military ranks or not.

By AD 410, the date usually given for the end of the Roman era, the Empire was riddled with internal conflicts and weakened by attacks in its own heartland. As the British at last stood up to it, rejecting the idea of government from the heart of the continent, they had sensed – correctly – that the Romans had neither the resources nor the administrative will to hold on to Britain. A celebrated letter from the then Roman emperor Honorius gave the command to withdraw troops, warning the British that they would have to look to their own defences from now on, and an era in our island’s history was at an end.