Offa's Dyke: section in Highbury Plains, 370m west of Birt's Barn

Overview

Heritage Category: Scheduled Monument

List Entry Number: 1020479

Date first listed: 24-Sep-1935

Date of most recent amendment: 24-Apr-2002

Map

Ordnance survey map of Offa's Dyke: section in Highbury Plains, 370m west of Birt's Barn
© Crown Copyright and database right 2018. All rights reserved. Ordnance Survey Licence number 100024900.
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Location

The building or site itself may lie within the boundary of more than one authority.

County: Gloucestershire

District: Forest of Dean (District Authority)

Parish: Newland

National Grid Reference: SO 53809 07946

Summary

Legacy Record - This information may be included in the List Entry Details.

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 Highbury Plains, 370m west of Birt's Barn 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 quarries, 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, as well as the building materials used.

History

Legacy Record - This information may be included in the List Entry Details.

Details

The monument includes the buried and earthwork remains of Offa's Dyke, 370m west of Birt's Barn, in Highbury Plains. Offa's Dyke generally consists of a bank up to 3.5m high with an intermittent ditch to the west and quarry ditches 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 western lip of the ditch. In this section, the Dyke is visible as a bank with quarry pits. The bank is about 10m wide at its base and stands to a maximum height of 2.5m on its western face and 1m on its eastern face. To the east of the bank are a series of quarry pits which are up to 8m wide and 0.4m deep. Deliberately laid stonework has been exposed at intervals along the western face of the bank, and may be interpreted as the remains of a dry stone revetment acting as a near vertical, and highly visible, facing to the western side of the Dyke. The lime kiln shown by the Ordnance Survey to the east of the line of the Dyke is in a ruinous condition, and is thought to date to the 19th century. The line of the Dyke is interrupted by a track which is now called Coxbury Lane and is thought to be an ancient routeway leading to Wyegate, an early medieval manor about 2km to the south of the point where the lane crosses the Dyke at Highbury. Where the lane crosses the Dyke, it is included in the scheduling. All fences, fence posts, gates, stiles, sign posts and the remains of the lime kiln 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: 33453

Legacy System: RSM

Sources

Books and journals
Fox, C, Offa's Dyke: A Field Survey of the Frontier Works of Mercia, (1955), 187,234
Hoyle, J, Vallender, J, Offa's Dyke in Gloucestershire: Management Survay, (1997), 69-74
Maclean, J, 'Trans. of the Bristol and Glos. Archaeological Society' in The Course of Offa's Dyke in Gloucestershire, , Vol. XVIII, (1893), 26

End of official listing