Hertfordshire Grim's Ditch: 990m long section between Crawley's Lane and Rossway Lane
Heritage Category: Scheduled Monument
List Entry Number: 1021205
Date first listed: 20-Feb-1929
Date of most recent amendment: 24-Feb-2004
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The building or site itself may lie within the boundary of more than one authority.
District: Dacorum (District Authority)
National Grid Reference: SP 95146 09186
Legacy Record - This information may be included in the List Entry Details.
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 some 18km. It does not appear that these principal sections were ever joined to form a continuous boundary. Current evidence suggests that the sometime 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 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 division separating, and perhaps enclosing, organised parcels of land and settlement. It may also have been used as 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 between Crawley's Lane and Rossway Lane survives well as a visible earthwork in the woodland at either end and as a partly buried feature along the central length and will provide 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. This section of Grim's Ditch is part of a larger stretch of Grim's Ditch between Wendover and Berkhamstead which follows an arc across the high ground above the Aylesbury Vale and Bulbourne Valley and following a similar course to the modern Ridgeway path less than one kilometre to the north west, which is itself a reflection of a prehistoric route along the line of the Chiltern Hills. Prehistoric hillforts are located close by, on Boddington Hill up to 6.5km to the west, Ivinghoe Beacon, 7.7km to the north and Cholesbury Hillfort 3km to the south west.
Legacy Record - This information may be included in the List Entry Details.
The monument includes a 990m long section of a prehistoric boundary known
as the Hertfordshire Grim's Ditch running broadly north west to south east
between Crawley's Lane and Rossway Lane, south of Smart's Wood.
The 1st edition Ordnance Survey map of 1896 shows this entire length of
the Hertfordshire Grim's Ditch as an extant earthwork. In subsequent years
the central section was denuded by ploughing and only slight intermittent
traces of the bank and ditch indicate the presence of buried
archaeological remains. Substantial earthworks survive in woodland at
either end of this section, spanning distances of some 150m to the north
west and 200m to the south east. In these areas the bank measures up to
1.8m high and 14m across. The accompanying sections of the ditch, to the
south of the bank, measure some 12m across and, although partly infilled
1.5m deep. At the north west end part of the ditch has been cut away by a
large extraction pit of uncertain date, which is not included in the
In 1973 excavations on a section of Grim's Ditch some 2.4km to the west
produced evidence of a level area, or berm, separating the bank and ditch
and a trench which would have supported a palisade along the outer edge of
the ditch. Similar components may also survive as buried features along
this section of the boundary.
Further sections of Grim's Ditch exist 700m to the west, west of Chesham
Road and 160m to the south east in Hamberlin's Wood. These sections and
others along the entire known route of the boundary are the subject of
All fences and fence posts, gates and telegraph poles 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.
The contents of this record have been generated from a legacy data system.
Legacy System number: 35347
Legacy System: RSM
Books and journals
Network Archaeology, , Grim's Ditch: Archaeological and Management Survey Phase III, (1999)
Title: Ordnance Survey 1st Edition Map Source Date: 1896 Author: Publisher: Surveyor: Herts XXXII
This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.
End of official listing