Although it had long been known to the Mediterranean peoples as a source of tin, Britain did not enter the Roman world until Julius Caesar’s arrival in 55 BC, a sort of afterthought to his conquest of Gaul. Caesar’s contact, however, was temporary; for permanent occupation had to wait until Rome had solved more pressing problems at home.
Emperor Claudius I invaded Britain in force in AD 43, but nearly two decades passed before the Romans had captured Anglesey, headquarters of the feared Druids, and put down the revolt of Boudicca, queen of the Iceni. The Roman governor Gnaeus Julius Agricola won the Battle of Mons Graupius (AD 84), in Scotland, but the northern tribes proved hard to subdue. In 123, Hadrian’s Wall, stretching 117 km (73 mi) from Solway Firth to the Tyne River, became the northern frontier.
Britain was a military outpost, taking a tenth of the Roman army to hold it. Several towns attained a degree of Roman urban civilization, boasting baths and amphitheaters, as well as people who spoke Latin and wore togas. Numerous villas and vast estates worked by slaves and featuring sumptuous noble dwellings were also established. Beyond these, the countryside remained Celtic.
Britain in the 3rd and 4th centuries felt the decline of the Roman Empire. An official known as the count of the Saxon Shore oversaw defenses against raids by Saxons and others along the North Sea coast. Would-be emperors stripped Britain of its occupying forces, moving the legions elsewhere to serve their own political ambitions. In 410 Rome abandoned Britain. After nearly four centuries of occupation, it left little that was permanent: a superb network of roads, the best Britain would have for some 1400 years; the sites of a number of towns: London, York, and others bearing names that end in the suffix -cester; and Christianity.
The Anglo-Saxons, who occupied the country after the Romans left, ignored the towns, chased Christianity into Wales, and gave their own names, such as Watling Street, to the Roman roads.