The Battle of Deorham was a decisive military encounter between the West Saxons and the Britons of the West Country in 577. The battle, which was a major victory for the Wessex forces led by Ceawlin and his son, Cuthwine, resulted in the capture of the Brythonic cities of Glevum, Corinium Dobunnorum, and Aquae Sulis. It also led to the permanent cultural and ethnic separation of Dumnonia from Wales. The Anglo-Saxon Chronicle is the only source that mentions the Battle of Deorham. Although it gives few details, it describes the battle as a major engagement. It was fought at Hinton Hill near Dyrham in South Gloucestershire.
Account
The Anglo-Saxon Chronicle entry for 577 records that that year King Ceawlin of Wessex and his young son Cuthwine fought the Britons of the West Country at "the spot that is called ". This is generally taken to be Dyrham in what is now South Gloucestershire, on the Cotswolds escarpment a few miles north of Bath. The West Saxons carried the day, and three kings of the Britons, whose names are given as Conmail, Condidan, and Farinmail, were slain. As a result of the battle, the West Saxons took three important cities, Glevum, Corinium Dobunnorum, and Aquae Sulis, representing Gloucestershire and Worcestershire east of the Severn, and a small part of northeastern Somerset.
The Severn Valley has always been one of the military keys of Britain, and some of the decisive battles of the Saxon conquest were fought to control it. In 577 Ceawlin advanced from the Thames Valley across the Cotswolds to seize the area and break the power of the Britons in the lower Severn area. Some historians have concluded that the Saxons may have launched a surprise attack and seized the hill fort at Hinton Hill Camp because it commanded the Avon Valley, and disrupted communications north and south between Bath and her neighbouring Romano-British towns of Gloucester and Cirencester. Once the Saxons were in occupation of the site the Britons of those three towns were compelled to unite and make a combined attempt to dislodge them. Their attempt failed and the three opposing British kings were killed. Their routed forces were driven north of the River Severn and south of Bath where it appears they began the construction of the defensive earthwork called the Wansdyke in a doomed attempt to prevent more territory from being lost. The military historian Lieutenant-Colonel Alfred Burne, employing his theory of 'Inherent Military Probability' opted for a simpler explanation for the battle than Baddeley. In his view Ceawlin was methodically advancing towards the Severn and the three forces of Britons concentrated to stop him. Burne suggests that they formed up along two slight ridges across the trackway that skirted the Forest of Braden, with Hinton Hill Camp behind them as their stores depot – a position similar to that adopted at the Battle of Beranburh in AD 556. Burne pointed out that if the Saxon attack drove the Britons back from their first line onto the second ridge near the edge of the escarpment, the slightest further retreat would leave their flanks open to a downhill pursuit. He speculates that this is what occurred, with the three Briton leaders and their main body being driven back into the fort while the flanking Saxons driving forwards swept round behind the promontory on which the fort stands. A last stand in this position would explain why none of the three Briton leaders was able to escape.
Outcome
The battle was a major military, cultural, and economic blow to the Romano-British because they lost the three cities of Corinium, a provincial capital in the Roman period ; Glevum, a former legionary fortress ; and Aquae Sulis, a renowned spa and pagan religious centre. Archaeological research has found that many of the villas in the post-Roman era were still occupied around these cities. This suggests the area was controlled by relatively sophisticated and wealthy Britons. However they were eventually abandoned or destroyed as the territory came under the control of Wessex. This quickly happened after the battle around the Cirencester region but the Saxons took many years to colonise Gloucester and Bath. Nevertheless these areas became part of the minor Anglo-Saxon England kingdom of Hwicce. Some academics believe the battle was also the starting point when Welsh and Cornish began to become two separate languages. Germanic-speaking Saxons now held the lands between the Celtic peoples in South West England and those in Wales and the English Midlands, whose territory would be conquered by the Angles of Mercia in the 8th Century. Others point out that, transport by water being then less costly than by land, contact by sea was still readily available, and indeed a Welsh genealogy record states that descendants from the kings of Pengwern founded a dynasty in the Glastonbury region in the 7th century.
