Details

The monument includes the buried and earthwork remains of Offa's Dyke, to
the north of Birchfield Cottage. 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 it was strengthened by additional earthworks,
namely a berm between the bank and ditch, and a counterscarp bank on the
outer lip of the ditch.

In this section the Dyke turns from its usual alignment to run some 49m
east-west. It is visible as a bank with quarry pits to the south. The bank
is up to 4m wide and stands to a maximum height of 0.7m. The quarry pits
cover an area approximately 2m wide and 0.2m deep.

An excavation was undertaken to the north of Birchfield Cottage between
1978 and 1979, but no features associated with Offa's Dyke were found.

All wooden fence posts, gate posts and stone walls are excluded from the
scheduling, although the ground them is included.

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

Source: Historic England

Reasons for Scheduling

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 at Birchfield Cottage survives well. 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 and the building materials used.

Source: Historic England

Sources

Books and journals
Fox, C, Offa's Dyke, (1955)
Hoyle, J, Vallender, J, Offa's Dyke in Gloucestershire: Management Survay, (1997)
Other
Ellis, P, A Watching Brief undertaken at Birchfield Cottage, 1979,

Source: Historic England