Grim's Ditch, Chilterns

Grim's Ditch near Hastoe

Grim's Ditch is a series of linear earthworks in the Chilterns, stretching across the border of Buckinghamshire and Hertfordshire (across the Tring Salient).

A complete outline cannot be identified but separate sections exist over a nineteen-mile span between Bradenham, Buckinghamshire, Berkhamsted, Hertfordshire and as far as Pitstone and Ivinghoe in Buckinghamshire.

The work is believed to have been created in the Iron Age as pottery shards were unearthed in excavations during the 1970s and 1980s suggesting that date. It is believed to have been during a period when the landscape was clearer of scrub and the dense woodland than today as the straighter sections would have required clear lines of sight.

The earliest surviving mention of Grim's Ditch is in a grant of 1170–90 in the Missenden Cartulary referring to it as Grimesdic. The name 'Grim's Ditch' is found applied to many similar earthworks in the southern and eastern counties and may refer to a by-name of the Anglo-Saxon god Woden, the god of war and magic. Another mention is to be found in a 10th-century boundary charter for the Mongewell area.

The size of the dyke varies considerably. At Hastoe the ditch is 11 feet wide and six and a half feet deep with a bank of six and a half feet and an overall spread of 44 feet. Its original purpose is uncertain and may be a set of local boundaries dating back to the Iron Age since it is not seen as having a defensive function due to the way that the banks have been constructed. Alternatively, the work may in fact be a collection of structures with two or more purposes, with the hilltop section near Cholesbury being associated with the nearby Iron Age hill-fort whilst other sections lower down towards Aylesbury Vale may demarcate areas where pig and cattle grazing occurred. Sections are scheduled as ancient monuments.

Graemesdyke Road, Berkhamsted

Route

Coordinates	Grid reference	nearby village
51°40’19"N, -0°47’35"W	SU834977	Bradenham
51°41’37"N, -0°48’30"W	SP823001	Lacey Green
51°43’7"N, -0°47’15"W	SP837029	Whiteleaf
51°42’43"N, -0°45’58"W	SP852022	Great Hampden
51°43’10"N, -0°42’39"W	SP890031	Great Missenden
51°45’0"N, -0°42’9"W	SP895065	The Lee
51°46’16"N, -0°39’46"W	SP922089	Cholesbury
51°46’34"N, -0°37’56"W	SP943095	Wigginton
51°45’34"N, -0°35’11"W	SP975077	Berkhamsted
51°46’15"N, -0°32’49"W	TL002090	Berkhamsted
51°45’57"N, -0°30’50"W	TL025085	Potten End

References

• 'Britain in the Dark Ages', 2nd ed. (Ordnance Survey, 1974)
• Davis, Jean (1981). "Grim's Ditch in Buckinghamshire and Hertfordshire". Records of Buckinghamshire.