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.
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.
