Wansdyke is a linear defensive earthwork dated to the Dark Ages around 400 AD, of truly amazing proportion: it runs at least from Maes Knoll in historic Somerset, a hillfort at the east end of Dundry Hill south of Bristol, to the Savernake Forest near Marlborough in Wiltshire. There is also some evidence in ancient charters that it extended west from Maes Knoll to the coast of the Severn Estuary but this is uncertain. Maybe it is not as familiar to many people as Offa's Dyke or Hadrian's Wall, yet it is one of the largest linear earthworks in the UK.
East Wansdyke. photo source unknown
Wansdyke was originally a large bank with a deep ditch in front, and runs in an east-west alignment, clearly pointing to a danger from the north. What was this danger? Who were the builders? The name points to the Saxon god Woden, but that does not mean that it was pagan Anglo-Saxons who actually built it. The name might mean it was only dedicated to Woden by pagan Saxons, or that it was already forgotten who the real builders were. Archaeological research now to a construction date in the 5th century.
Wansdyke consists of two sections of 14 and 19 kilometres (9 and 12 miles) long with some gaps in between. East Wansdyke is an impressive linear earthwork, consisting of a ditch and bank running approximately east-west, between Savernake Forest and Morgan's Hill. West Wansdyke is also a linear earthwork, running from Bath to Maes Knoll south of Bristol, but less impressive than its eastern counterpart. The middle section, 22 kilometres (14 miles) long, is sometimes referred to as 'Mid Wansdyke', but is formed by the remains of the Roman road from Bath to London. It used to be thought that these sections were all part of one continuous undertaking, especially during the Middle Ages when the pagan name Wansdyke was applied to all three parts. However, it is not now considered certain that this is so.
East Wansdyke in Wiltshire, on the south of the Marlborough Downs, has been less disturbed by later agriculture and building and remains more clearly traceable on the ground than the western part. Here the bank is up to 4 m (13 ft) high with a ditch up to 2.5 m (8.2 ft) deep. Wansdyke's origins are unclear, but archaeological data shows that the eastern part was probably built during the 5th or 6th century. That is after the withdrawal of the Romans and before the takeover by Anglo-Saxons. The ditch is on the north side, so presumably it was used by the Celts as a defence against Saxons encroaching from the upper Thames valley westward into what is now the West Country.
Although the antiquarians like John Collinson considered West Wansdyke to stretch from south east of Bath to the west of Maes Knoll it was shown in 2007 that the West Wansdyke continues from Maes Knoll to the hill forts above the Avon Gorge and controls the crossings of the river at Saltford and Bristol as well as at Bath.
As there is little archaeological evidence to date the western Wansdyke, it may have marked a division between British Celtic kingdoms or have been a boundary with the Saxons. The evidence for its western extension is earthworks along the north side of Dundry Hill, its mention in a charter and a road name.
The area of the western Wansdyke became the border between the Romano-British Celts and the West Saxons following the Battle of Deorham in 577 AD. According to the Anglo-Saxon Chronicle, the Saxon Cenwalh achieved a breakthrough against the British Celtic tribes, with victories at Bradford-on-Avon (in the Avon Gap in the Wansdyke) in 652 AD, and further south at the Battle of Peonnum (at Penselwood?) in 658 AD, followed by an advance west through the Polden Hills to the River Parrett.
When the Saxons came upon the dyke, they named it after their god Woden, hence it became 'Woden's Dyke' and, eventually, Wansdyke. Its name occurs in charters of the 9th and 10th century AD. as one of the largest defensive earthworks in the United Kingdom. Nennius, an 8th century Welsh monk who had access to older chronicles since lost, describes these defences and their purpose, and links them to the legends of King Arthur.
The above Wansdyke photographs in colour by Jake Livingston and Joe Boyles.