Reasons for Designation
Linear boundaries are substantial earthwork features comprising single or
multiple ditches and banks which may extend over distances varying between
less than 1km to over 10km. They survive as earthworks or as linear features
visible as cropmarks on aerial photographs or as a combination of both. The
evidence of excavation and study of associated monuments demonstrate that
their construction spans the millennium from the Middle Bronze Age, although
they may have been reused later.
The scale of many linear boundaries has been taken to indicate that they were
constructed by large social groups and were used to mark important boundaries
in the landscape; their impressive scale displaying the corporate prestige of
their builders. They would have been powerful symbols, often with religious
associations, used to define and order the territorial holdings of those
groups who constructed them. Linear earthworks are of considerable importance
for the analysis of settlement and land use in the Bronze Age; all well-
preserved examples will normally merit statutory protection.
The boundary known as the Buckinghamshire and Hertfordshire Grim's Ditch
includes numerous surviving sections from within three main linear earthworks
aligned along the Chiltern Hills between Bradenham and Berkhamsted and
spanning a total distance of 18km. It does not appear that these principal
sections were ever joined to form a continuous boundary. Current evidence
suggests that the sometimes quite sizeable gaps represent areas which were
formerly forested, or in which natural features served to perpetuate a
division of the land. The same pattern has been discerned along the North
Oxfordshire Grim's Ditch to the west of the Thames. A further comparable
linear boundary, the Moel Ditch, extends to the east across parts of
neighbouring Bedfordshire.
For the most part the visible sections of Grim's Ditch in the Chilterns
include a wide single ditch flanked by a bank of upcast earth, which is
always upslope of the ditch. Other features, discovered by limited
excavation include a turf core within the bank, a berm separating bank and
ditch (concealed over time by the spread of bank material) and a trench
for a fence or palisade, along the outer rim of the ditch. The
Buckinghamshire and Hertfordshire Grim's Ditch is thought to have served
as a territorial boundary, separating, and perhaps enclosing, organised
groups of land and settlement. It may also have been an agricultural
boundary, denoting grazing areas and impeding the movement (or theft) of
stock. Excavations to date have provided only limited dating evidence.
Pottery recovered from the fill of the ditch indicates that it was in
existence in the Iron Age. As such, the boundary provides important
evidence for the management of the landscape in the centuries preceding
the Roman Conquest in AD 43, although it may have a considerably earlier
origin. It remained a notable feature in later centuries, acquiring its
present name (a variation on the name of the god, Odin) at some point in
the early medieval period, perhaps during the period of pagan Saxon
settlement in the 5th and 6th centuries. The earliest recorded use of the
term, `Grim's Ditch' occurs in a charter granted by Edward, Earl of
Cornwall, in 1291.
All sections of the Buckinghamshire and Hertfordshire Grim's Ditch which
survive in visible form, or as well-preserved buried remains (identified
by aerial photography or ground survey), are considered integral to a
general understanding of the monument and will normally merit statutory
protection. The section of Grim's Ditch from Great Widmoor Wood to Oaken
Grove survives well as a visible earthwork along most of its length and
provides a fascinating insight into the nature of early territorial land
division in the Chiltern Hills. It will contain archaeological evidence
for the manner of its construcion as well as environmental evidence for
the appearance of the landscape in which it was built. The archaeological
evidence may also include artefacts or scientific dating material from
which to determine the period of its construction and the duration of its
maintenance as an active boundary. The stretch of Grim's Ditch between
Wendover and Berkhamstead follows an arc across high ground above the
Aylesbury Vale and Bulbourne Valley. Prehistoric hillforts are located
close by on Boddington Hill, 1.75km to the north west and Cholesbury
Hillfort 3km to the east.
Details
The monument includes a 1500m long section of a prehistoric boundary known
as the Buckinghamshire Grim's Ditch, which runs broadly north for 320m
along the west side of Great Widmoor Wood and into Mercer's Wood before
changing direction and running in a north east direction for 1180m along
the north west edge of Baldwin's Wood and through Oaken Grove.
The section of the Grim's Ditch sited on high ground from Great Widmoor
Wood to Oaken Grove survives as a clearly visible bank and ditch along
most of its length. The ditch measures up to 8m wide and 1.6m deep, and
has been infilled in places. To the west and north of the ditch lies a
parallel bank, approximately 7m wide and standing up to 1m in height. To
the south west of Oaken Grove a 160m section of the boundary has been
levelled by cultivation over the years, but the bank and ditch survive as
buried features, identified as cropmarks on an aerial photograph of 1988.
In the 190m section between Mercer's Wood and Baldwin's Wood the ditch is
similarly under cultivation, and is also believed to survive as a buried
feature. An excavation, carried out in 1973 along a section of Grim's
Ditch approximately 3km to the north east, produced evidence of a level
area, or berm, separating the bank and ditch. A palisade trench, which
would have supported a wooden fence, was also found along the outer edge
of the ditch. Similar components may survive as buried features along this
section of Grim's Ditch.
In the area of Mercer's Wood the monument changes direction from north
east-south west to north-south creating a dog-leg. Here the bank and ditch
are less substantial than elsewhere. It has been suggested that there may
originally have been a break in the monument at this point and that the
two separate lengths were joined together at a later date. The prehistoric
boundary is also affected by later activities elsewhere, notably by a
large extraction pit cut across the monument towards the north of
Baldwin's Wood and by a small pit cut through the bank in Mercer's Wood.
Unmetalled track surfaces cross the monument at various points. Further
sections of Grim's Ditch exist, immediately north of Oaken Grove and some
2km to the south near Cottage Farm, and these sections and others along
the entire known route of the boundary are the subject of separate
schedulings. It is possible that there was a break in the boundary between
the second of these two sections and Great Widmoor Wood.
All fences, walls, gates and stiles are excluded from the scheduling,
although the ground beneath them is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.
