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
excavations, include a turf core within the bank, a berm separating bank
and ditch (concealed over time by the spread of the 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 it's
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 360m long section of Grim's Ditch 330m south east of
Hampden House 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 construction 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.
Details
The monument includes a length of the prehistoric boundary known as the
Buckinghamshire Grim's Ditch located on high ground to the south west of the
dry valley between Hampden Bottom and Buckmoorend. Hampden House, a large
country mansion which was first built in this prominent location in the 14th
century, lies immediately to the north west and is approached by a main
driveway which follows the southern edge of the earthwork. Hampden House
is Listed Grade I.
The substantial remains of Grim's Ditch start at the boundary of Hampden
House's immediate grounds, some 130m south east of the mansion, and continue
alongside the drive for approximately 360m before terminating at the
crossroads to the east of Hampden House Lodges. The earthen bank measures up
to 7m wide and stands up to 0.8m high in some places. To the east of the bank
lies a parallel ditch, up to 7m wide and up to 0.7m in depth. Excavations,
carried out in 1973 and 1991 along other sections of Grim's Ditch, produced
evidence of a level area, or berm, separating the bank and ditch. Evidence for
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 the Grim's Ditch.
Further sections of Grim's Ditch exist to the west in Hampden Park and to the
east in Oaken Grove. These sections and others along the entire known route of
the boundary are the subject of separate schedulings.
All fences, fenceposts and road surfaces 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.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.
