Grim’s Ditch

Grim’s Ditch

Neither grim nor really a ditch

Grim’s Ditch defines the northern boundary of Cholesbury-cum-St Leonards Parish. It runs from The Lee across The Hale, through Hastoe and towards Wigginton. This example of the ancient linear earthworks is one of a number to be found along the Chilterns escarpment. The other sections run between Pitstone and Ivinghoe to the Northeast, Lacey Green to Hampden to the South West and beyond this there is a further section at Nuffield in Oxfordshire.

Although collectively known as Grim’s Ditch it is generally agreed that these landmarks probably have more than a single origin. The Anglo Saxons commonly named features of unexplained or mysterious origin, ‘Grim’. The word derives from the Norse word grimr meaning devil and a nickname for Odin or Wodin the God of War and Magic. Grim’s Ditch or Dyke is not confined in usage to this part of England being found both in Yorkshire and the West Country. The earliest recorded mention of the Grim’s Ditch in these parts was from an 1170 Missenden Cartulary, a manuscript recording land in the ownership of the then newly founded Missenden Abbey.

Archaeological excavations during the 1970’s and 80’s revealed small shards of locally made pottery and napped flints confirming that the earthwork was of Iron Age origin and was probably constructed around the second millennium BC. They have also confirmed that the earthwork’s purpose was not defensive because the earth extracted to create the ditch was not used to create a steep rampart. During original construction spoil from the ditch was heaped up into a gentle mound on one side making the whole earthwork more than 13 metres wide. Examination of the soil composition has determined that the ditch was deeper at Cholesbury than elsewhere in the Chilterns, being over 2 metres deep and 3.5 metres wide. The manner in which the ditches are orientated in the landscape and the types of snail shells found in deposits also suggests that the area would have been clear of woodland and scrub at the time of construction.

Tribal communities

Despite not being a ‘military’ structure there is conjecture though of a possible association between Cholesbury hill-fort and this section of Grim’s Ditch, both being of a similar age. Some historians suggest Grim’s Ditch defined the boundary between the territories of neighbouring tribal communities. It is known that the lands stretching from the Chiltern Hills southwards was part of the territory held by the Catuvellaunian people. Alternatively, Grim’s Ditch could be the boundary line separating the upper common grazing pastures from the more fertile lowland arable land which was farmed in thinly divided strips running up the Chiltern escarpment from the area now known as the Vale of Aylesbury.

It is difficult to imagine nowadays how imposing Grim’s Ditch would have appeared in Iron Age Britain and subsequently to the Saxons. Whatever, its purpose it was a massive and impressive undertaking and confirms that sophisticated organisation of communal labour would have been required to construct and maintain it. Today it looks more like a track-way or field boundary. The original earthworks having been progressively rubbed out by ploughing adopted as a footpath or obscured under heavy scrub or woodland. Nevertheless if one walks along the short length that demarcates the northern edge of the parish and take in the views it dictates, it leaves one in no doubt of the significance of Grim’s Ditch to the ancient British.


Reference: J. Davis Grim’s Ditch in Buckinghamshire and Hertfordshire in Records of the Buckinghamshire Archaeological Society 1981

Chris Brown
September 2001