This is because the Roman Empire was continually involved in civil wars even after his demise. This all changed once to Romans arrived.
Early Romans kept no written records. Once the empire collapsed Britain went back to relying simply on agriculture in order to make a living.
They built their roads on foundations of clay, chalk and gravel. Julius Asclepiodotus landed an invasion fleet near Southampton and defeated Allectus in a land battle. Introduction People like him were rare. Rome controlled its provinces by bribing the local elite.
After Vespasian secured the empire, his first two appointments as governor, Quintus Petillius Cerialis and Sextus Julius Frontinustook on the task of subduing the Brigantes and Silures respectively. Julia was killed when Caesar was in Gaul. It encompassed many different cultures that fell under Roman political rule.
Emperors made laws against paganism, idolatry, and sacrifices. After it fell, Constantius attacked Carausius's other Gallic holdings and Frankish allies and Carausius was usurped by his treasurer, Allectus.
Its governors went on to become emperors, and it was a powerbase for a host of rebels.