Offa's Dyke: section in Boatwood Plantation, 320m south west of Chase Farm

Reasons for Designation

Offa's Dyke is the longest linear earthwork in Britain, approximately 220km, running from Treuddyn, near Mold, to Sedbury on the Severn estuary. It was constructed towards the end of the eighth century AD by the Mercian king Offa, and is believed to have formed a long-lived territorial, and possibly defensive, boundary between the Saxon kingdom of Mercia and the Welsh kingdoms. The Dyke is not continuous and consists of a number of discrete lengths separated by gaps of up to 23km. It is clear from the nature of certain sections that differences in the scale and character of adjoining portions were the result of separate gangs being employed on different lengths. Where possible, natural topographic features such as slopes or rivers were utilised, and the form of Offa's Dyke is therefore clearly related to the topography. Along most of its length it consists of a bank with a ditch to the west. Excavation has indicated that at least some lengths of the bank had a vertical outer face of either laid stonework or turf revetment. The ditch generally seems to have been used to provide most of the bank material, although there is also evidence in some locations of shallow quarries. In places, a berm divides the bank and ditch, and a counterscarp bank may be present on the lip of the ditch. Offa's Dyke now survives in various states of preservation in the form of earthworks and, where sections have been levelled and infilled, as buried features. Although some sections of the frontier system no longer survive visibly, sufficient evidence does exist for its position to be accurately identified throughout most of its length. In view of its contribution towards the study of early medieval territorial patterns, all sections of Offa's Dyke exhibiting significant archaeological remains are considered worthy of protection.

The section of Offa's Dyke in Boatwood Plantation, 320m south west of Chase Farm, survives well, and illustrates the use of natural topography to enhance the form and visibility of the Dyke. The bank will have preserved part of the original ground surface, predating the construction of the monument and, along with the berm to the south and the quarries to the north, will contain environmental evidence in the form of organic remains which will relate both to the Dyke and to the landscape within which it was constructed. The bank will also contain evidence relating to the methods of construction of the monument and the building materials used.

Details

The monument includes the buried and earthwork remains of Offa's Dyke in Boatwood Plantation, 320m south west of Chase Farm. This section of Offa's Dyke is in the care of the Secretary of State. Offa's Dyke generally consists of a bank up to 3.5m high with an intermittent ditch to the west and quarries to the east. In places Offa's Dyke was strengthened by additional earthworks, namely a berm between the bank and ditch and a counterscarp bank on the lip of the ditch.

This 364m long section of the Dyke turns from its usual alignment to run north west-south east. It is visible as a bank with a berm on its south side and contiguous quarry pits to the north. The bank is up to 17m wide at its base and stands to between 2.5m and 3.5m high on its southern face and to between 0.8m and 1.8m on its northern face. The berm is about 2m wide and represents an artificial break in slope at the base of the earthen bank. The quarries are up to 10m wide and about 1m deep. A stone boundary wall, which is thought to date from the mid to late 19th century, runs along the top of the bank throughout the length of this scheduling. There is a gap in the Dyke at Ordnance Survey NGR ST54929845 formed by the cutting of a forestry access road, material from which was thrown up to form a bund. It is not thought to represent an original crossing point through the monument.

The metalled surface of the forestry track, all fence posts, sign posts, marker posts, telegraph poles and the stone wall which runs along the top of the bank are excluded from the scheduling, although the ground beneath these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.

Legacy

The contents of this record have been generated from a legacy data system.

Legacy System number:

34852

Legacy System:

RSM

Sources

Books and journals
Hoyle, J, Vallender, J, Offa's Dyke in Gloucestershire: Management Survay, (1997)

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