A Brief History of Birmingham
The Dark Ages
The period from the end of the Roman Empire to the Norman Invasion is often now called the Early Middle Ages. The westward movement of central Asian people such as the Huns and the Goths may have been due to climatic conditions. During cooler periods the meltwaters of central Asian glaciers gave a plentiful water supply even at the edges of the deserts. However a warmer climate led to the water supply diminishing, the desert area encroaching and communities moving to more favourable sites. Pressure of migration from the east led eventually to the fall of the Roman Empire. These population movements were to include the Anglo-Saxons.
410 AD is the date traditionally taken as marking the end of Roman Britain. In that year that Emperor Honorius is thought to have answered the British request for help against invaders by telling the Britons that they must defend themselves. In the same year Rome fell to Alaric the Visigoth. There is almost no written evidence for what happened after that and so little archaeological evidence that the period which saw the end of Romano-Celtic Britain and the arrival of the Anglo-Saxons is usually called the Dark Ages.
It is assumed that, as the withdrawal of Roman authority gradually became apparent, Romano-Celtic leaders took charge of the Roman regions; these were probably roughly based on original Celtic tribal areas. The Corieltauvi were east and north of Birmingham with their capital at Leicester, the Cornovii west and north of Birmingham with their capital at Wroxeter, the Dobunii to the south of Birmingham with their capital at Cirencester. These areas probably reverted to Celtic tribal control.
With the collapse of Roman economic and administrative systems town life declined rapidly and power focussed once more on hillforts and large agricultural estates. The Birmingham plateau probably remained a border region between the three tribal areas the precise boundaries of which are unknown and may not have existed at all.