Offa's Dyke: section on Madgett Hill, 290m south east of Brook House


Heritage Category: Scheduled Monument

List Entry Number: 1020598

Date first listed: 16-Sep-1935

Date of most recent amendment: 03-Sep-2002


Ordnance survey map of Offa's Dyke: section on Madgett Hill, 290m south east of Brook House
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The building or site itself may lie within the boundary of more than one authority.

County: Gloucestershire

District: Forest of Dean (District Authority)

Parish: Hewelsfield and Brockweir

National Grid Reference: SO 54557 01456


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 290m south east of Brook House on Madgett Hill survives well. The bank will have preserved part of the original ground surface, predating the construction of the monument, and along with the quarries to the east, will contain environmental evidence in the form of organic remains which will relate both to the Dyke and to the landscape in which it was constructed. The bank will also contain evidence relating to the methods of construction of the monument and the building materials used. The reuse of the bank as part of a medieval mill complex is unusual and indicates that it had survived as a significant earthwork until that period.


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


The monument includes the buried and earthwork remains of Offa's Dyke 290m south east of Brook House on Madgett Hill. Offa's Dyke generally consists of a bank up to 3.5m high with an intermittent ditch to the west and quarry pits 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 54m long section, the Dyke is visible as a bank with shallow quarry pits to the east and runs north-south at the base of Madgett Hill. The bank is about 12m wide at its base and stands to a maximum height of 2.3m on its western face and 1.1m on its eastern face. Quarry ditches are visible on the eastern side of the bank along the entire length of the section, surviving to a maximum depth of 0.9m and to a width of between 2m and 4m. The bank in this section has been revetted on both sides with stone walling and appears to have been reused as part of a later (probably medieval) mill complex. Overgrown linear rubble spreads to the west of the bank may indicate the remains of buildings associated with the complex. The purpose for which the bank of the Dyke was revetted is unclear, although as the area between the walls is flat, it may have been intended to create a causeway leading to a now lost bridge over the stream and allowing access for vehicles to the mill from both sides of the watercourse. All fence posts and stiles 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.


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

Legacy System number: 33474

Legacy System: RSM


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

End of official listing