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 Passage Grove, 660m west of Sheepcot,
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 ditch and counterscarp bank and 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 Dyke and the building materials used.
Details
The monument includes the buried and earthwork remains of a section of Offa's
Dyke in Passage Grove, 660m west of Sheepcot. This section of the 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 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 lip of the ditch.
In this 539m long section the Dyke is visible as a bank with a ditch and
counterscarp bank to the west and quarry pits to the east. The main bank is
between 14m and 16m wide at its base, and is up to 5.1m high on its western
face and 1.4m on its eastern face. The ditch to the west of the bank is
between 4m and 6m wide and is up to 0.7m deep, while the counterscarp bank
rises to 0.7m. To the east of the main bank is a group of contiguous quarry
pits which are up to 2.2m deep and between 5m and 8m wide.
The line of the Dyke makes use of the natural topography of the area, running
along the top of a steep scarp slope, which would have made the Dyke highly
visible from the west bank of the River Wye.
All fence posts are excluded from the scheduling, although the ground
beneath them are included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
