GRIM'S DITCH IN BUCKINGHAMSHIRE AND HERTFORDSHIRE JEAN DAVIS Past work on the Chi/tern stretches of Grim's Ditch is recalled, with particular reference to the dykes on the Pitstone hills. The discovery, in 1980, ofcrop marks related to two further stretches of ditch is described. A section dug through one of them is illustrated, and evidence bearing on the second ditch is discussed. Comparison is made with a length of Grim's Ditch at Hastoe, Hertford- shire, excavated in 1973, a section of which is here published for the first time. Introduction near Cholesbury, Bucks. (SP 9190 0882). A It was during fieldwork for the Viatores' short report of the excavation appeared in study of Roman roads in the Chilterns that R. Rec. Bucks. XIX part 3, 1973, p. 345, but no W. Bagshawe first recognised the significance diagram was published. The scope of the exca­ of the earthworks on the Pitstone hills, at that vation was limited by the amount of time al­ time unrecorded. He alerted James Dyer; and lowed by the owner of the property and the the result was the publication, in Records of findings were not surprisingly inconclusive: Buckinghamshire, of "Pitstone Hill- A Study nevertheless, the shape of the section was es­ in Field Archaeology" by J. F. Dyer and A. J. tablished and the form of contruction sur­ Hales (Dyer & Hales, 1962), to be followed in mised. A small piece of poorly fired shaly Iron the next year by Dyer's "The Chiltern Grim's Age pottery, of a type made locally over a long Ditch" (Dyer, 1963). period, was found in the top few centimetres of the bank core, giving a terminus post quem These surveys sought to establish that the for the construction of the bank above. two broken lengths of Grim's Ditch already identified (the first near Great Hampden, the A further small excavation was done the second from King's Ash to the outskirts of same year near Shootersway in Berkhamsted Berkhamsted) were continued by a further arc (SP 972 081), the ditch in this case being of ditch-and-bank in the area between roughly similar in shape and dimensions to Aldbury and Ivinghoe Beacon, thence that at Hastoe. Four small pieces of Iron Age extending the system further north-east along pottery were found, but of a different type. the Chilterns. Earlier work on the Chiltern In 1976 James Dyer contributed a report to Grim's Ditch by Dr. 0. G. S. Crawford CBA Group 9, in which he referred to the (Crawford, 1931) had included a mention of need for further work on the Pitstone hills. the stretch of dyke by that name on What follows should be seen as no more than a Berkhamsted Common as part of the series of footnote to the studies already made, in the earthworks: this was disputed by James Dyer, light of further evidence which has emerged who thought it later. recently: and it should be read in conjunction with Dyer's 1962 article referred to above, Little further work was done on Grim's which includes much valuable detail here Ditch until Easter, 1973, when a party led by omitted. two archaeology graduates from Sheffield University, N. J. Davis and R. Whinney, ob­ Few firm conclusions are drawn in this pre­ tained permission to cut a section through that sent report, but one or two suggestions are part of the ditch which runs through Hastoe, made for future thought and action. 23 / --~~~··~·----~~========~NO~AO$ ... M /'/ SOOM / l 'h -• Couneoldyke lb1nk1nd/or ditch,orcropmark.l Pilri•h Boundary CountvBoundrv .. \ \ ' Fig. 1. Grim's Ditch between Aldbury and Ivinghoe. The newly discovered lengths are at the top. 24 With Mr. Dyer's permission his terminology The banks were incorporated in the Aldbury has been adopted throughout, except for the open field system, but survive where virtually name of the small hill referred to by him as the all traces of other boundaries or headlands "Citadel" which is herein referred to by its have been ploughed out, indicating their origi­ local name, "Wadborough Hill". nal massive size. A third, partly curving, bank further west can also be seen. The precise re­ I should like to thank Mr. Dyer and Mr. lationship between these banks and the Bagshawe, both of whom have been consulted lengths of dyke which are next described is not before this report is submitted; the excavators clear; but, by being seen to go a considerable of the Hastoe section, for permission to in­ way across open low ground, the banks in the clude their hitherto unpublished sectional Aldbury valley are an unusual and perhaps sig­ diagram; and the members of the Pitstone nificant feature when most of the existing Local History Society who worked on the most stretches of Grim's Ditch run at a higher level. recently discovered length of ditch.. I am grateful to Mr. Michael Farley, who inspected The only lengths of dyke in Aldbury desig­ the site of the excavation and gave advice. In nated "Grim's Ditch" on the most recent particular I owe a debt of gratitude to Mr. Ordnance Survey 1:2500 map are those John Chenevix Trench, who has not only been marked E-F and G-H. It is unfortunate that a constructive critic but has provided the maps the routing of the Ridgeway Path past Aldbury on which this article is based. Nowers arid across the hills has inevitably brought a great deal more foot traffic: the The Pitstone Hills Reviewed Aldbury section in particular has suffered, as The areas of Aldbury, Pitstone and the path runs for considerable distances along Ivinghoe parishes to which this article relates the bank instead of in the ditch. In the past few are identified in Figure 1; it does not show the years, much erosion has taken place and the site of the Hastoe excavation, to which further dyke is far less impressive than it was some reference is made below. The lengths of dyke years ago. referred to by Dyer and Hales form the basis of Figure 1, to which other recently identified Between F and G, Dyer did not record any features have been added. Discussion of the earthwork through Aldbury Nowers. Shortly dykes is here generally limited to these specific after leaving F, however, the path through the features. woods runs along the upper edge of a stretch of shallow ditch, and a similar shallow ditch lies In his Antiquity paper of 1963, p. 47, James some 12 to 14m. downhill. The upper ditch ap­ Dyer refers to a cropmark to the south-east of pears to lie on the boundary between the Now­ the road from Aldbury to Tring Station (SP ers on the east and Turlhangers on the west 956 123) which he saw as the beginning of the (not distinguished from the Nowers on Dyer's run of Grim's Ditch via Pitstone Hill to Steps map). The lower ditch takes a roughly parallel Hill. In fact this shows, not only as a cropmark course along the shoulder of the hill. As the and in aerial photographs, but as a distinct course of these shallow ditches at their south­ bank, particularly in light snow or after ern extremity diverges from the trend of the ploughing, and it is paralleled by another bank dyke, it is questionable whether they are part some 160 m. nearer Tring Station (Fig. 1, A­ of the dyke system, and they are omitted from B, C-D). The banks stretch two-thirds of the Figure 1. way across the big field known as Stool Field; both Station Road and Stool Baulk, which Above Northfield Grange the upper ditch once divided Upper and Lower Stool Fields emerges from the wood and becomes more and runs at right-angles to these banks, rise pronounced in depth: it is once more desig­ and fall slightly as they cross the first of them. nated Grim's Ditch by the Ordnance Survey 25 ····--·····' ··' ' 'l)O .•' / ... ' ...,§\ ' ' / .Mfiona.l7T~~ 7ield. I f / f .......................... '·· 160 ••··· ·· 170 ,. ...- ~?,0 .. I ' ) J I I I I .. Fig. 2. Newly discovered lengths of Grims Ditch in Pitstone and Ivinghoe. 26 from this point to the parish boundary. The between the one first noticed and the hedge lower parallel ditch disappears without trace which separates National Trust Field from in the scrub of Pits tone Hill Lammas Ground. Wadborough Hill Field to the south-east. The cause of the first of these two hillside crop­ Because of scrub clearance on the Pitstone marks proved on exploration to be a deep hills during the winter of 1979--80, many of the ditch (henceforth Dyke V to conform with Mr. earthworks there are clearer than for many de­ Dyer's sequence), the more fertile contents of cades and the course of the dykes is easy to fol­ which contained a reservoir of nourishment low. At point J, Dyer notes that the ditches for the wheat in the spring, when the rest of the have faded out; this is doubtless because Wad­ crop was languishing in the drought on very borough Hill was under the plough until the shallow topsoil. The wider cropmark, al­ last war. He sees them reappearing on Steps though not then excavated, was assumed to Hill to the north-east, dying out finally near have a similar cause. the top of the hill at N. As will be seen be­ lowhowever, the discovery of a new length of The hillside cropmarks reappeared in the one ditch (K-L), and the signs of a second, subsequent spring, but there was no sign of complicate rather than simplify the possible them in 1982.