Dr Erik Grigg
Bishop Grosseteste University, Lincoln
The High Dyke in Cambridgeshire is an example of a little understood type of feature, an early medieval dyke. By dyke I don’t mean a drainage ditch (though it is in an area that understandably has quite a few), but a long linear bank constructed from material dug from an adjoining ditch dating from what used to be called the Dark Ages, that is, the centuries after the end of Roman rule. It is often considered to be part of Fleam Dyke, another better-known earthwork that also faces south (that is the bank is on the north side of the ditch) a few miles to the east (Malim et al 1996). There is a large gap between the two and Fleam is slightly curved while the High Dyke is dead straight, even if they were built for similar reasons and during the same broad period of history, the High Dyke is surely worthy of consideration on its own.
Such features are hard to put a date on as we have no documents recording them being built and unlike graves or settlements, a hole in the ground and a bank of earth rarely have any finds buried in them (though they often bury older features). High Dyke is unusual as a series of early medieval artefacts have been found in the monument, but these were not properly recorded using modern archaeological methods. In 1947 a shield boss was dug up, ten years later a group of skeletons with classic ‘Anglo-Saxon’ grave goods (a sword, a pommel, various spearheads, a knife and some brooches) were found and in 1963 another shield boss discovered (R.C.H.M.E. 1972 pp. 144-47). Late Roman coins found under the bank of Fleam Dyke and radiocarbon dating of organic material from the ditch fill confirms it also was built around or just after the end of Roman rule.
Late Roman coins found under the bank of Fleam Dyke and radiocarbon dating of organic material from the ditch fill confirms it also was built around or just after the end of Roman rule
Such earthworks have fascinated me since being a teenager when I discovered similar enigmatic dykes in Dorset, so much so that when I did a PhD at the University of Manchester a decade or more ago, I spent seven years visiting, surveying and writing about them (Grigg 2018). Although there slightly similar earthworks dating from the prehistoric and some later medieval dykes, the hundred I studied all seemed to be similar in location and size (up to two miles long with banks one to two metres high and six to ten metres wide) with archaeological finds or records of medieval charters (these often mention them as landmarks) seeming to confirm that the period 400 CE to 850 CE saw a lot of digging in this country.
The items found at High Dyke are unusual but not unique. Bodies and weapons have been found at other early medieval earthworks including Bran’s Ditch, the Devil’s Ditch, a linear earthwork at Heronbridge in Cheshire and various other such dykes. In the centuries after the end of Roman rule and before Christianity became the dominant religion, people were often buried with weapons so these finds could just be disturbed graves. Though not everyone buried with a sword and a shield was necessarily a warrior, the fact that it was common to bury people with weapons does suggest a society that valued being able to handle such things. The finds from the High Dyke could mean that the ditch was used as a convenient place to bury somebody who the mourners thought should be placed at rest with a sword and shield. However, at some sites the bodies are in unusually large numbers or there is evidence of cut marks to the bones or they have been buried in pieces (just a skull or the skeleton being incomplete) which suggests that we may be looking at people who died violently. They may have been executed or died in a fight. This does not prove that these earthworks had a warlike function (they may have had more than one), but with no domestic objects coming from any of these earthworks (unless they are residual Roman finds from under the banks or the odd brooch found with a body) we cannot rule out people who first used the dykes had some interest in death and violence.
However, at some sites the bodies are in unusually large numbers or there is evidence of cut marks to the bones or they have been buried in pieces which suggests that we may be looking at people who died violently.
There are famous early medieval dykes like Offa’s Dyke and Wansdyke that meander across the landscape for long distances, but they are not typical, High Dyke is in being just over a mile long. Most seem to cut across roads, they bisect ridgeways or causeway or slice valleys that carried trackways. Archaeologists have debated for years if they ever had gateways, but I have yet to see any convincing evidence of one. My theory is that they were designed to block routeways, they are rarely aligned with county or parish boundaries (High Dyke is ignored by both) so rather than being borders, they were probably set back from them and were places where the locals could gather if they got warning of a hostile raiding party to bar their access. Some have suggested that they had wooden palisades on the banks, but there is no evidence of postholes found in any of them. The bank at High Dyke has been severely damaged by having a later road running along it, perhaps this sort of destruction is why the postholes are gone? Well, if we look other structures with earth banks like prehistoric hillforts, Roman marching camps or medieval ringworks (castles with just donut-shaped earthworks) or Anglo-Saxon burhs (forts or fortified towns), we can always find the postholes somewhere; if these dykes had a palisade, then if is incredibly unlikely that no excavation has ever found a posthole.
The High Dyke is unlike the other nearby Cambridgeshire Dykes like Fleam Dyke that seem to block access along the Icknield Way to anyone wishing to enter East Anglia from the Midlands. Unlike most early medieval dykes that usually cut a road, High Dyke seals off the entrance to what would have been a peninsula of high(-ish) ground surrounded by fens (now it is the River Cam on the west, the Bottisham Lode to the north and Quy Water to the east). Does that mean that this peninsula (which is covered by the northern half of Fen Ditton and the village of Horningsea) was a special place, say with ritual or religious significance or perhaps the headquarters of the local elite? Not necessarily. There is evidence of some Romano-British settlement in this area but nothing special, no feature that suggested that it was unusual (though who knows what lies awaiting discovery). The earthwork itself probably required the shifting of ten thousand cubic metres of earth, my calculations suggest that with early medieval tools between 40 and 70 people could have built it over a Summer (the soil would have been too damp in other seasons). It was quite an easy job to do for the inhabitants of a couple of villages, a few hamlets or half a dozen farms to build this unusual feature.
Unlike most early medieval dykes that usually cut a road, High Dyke seals off the entrance to what would have been a peninsula of high(-ish) ground surrounded by fens
There are other earthworks that might date from this period that cut off peninsulas that like the High Dyke do not seem to contain any known sites of important archaeological significance. Park Pale near Topcliffe in Yorkshire, various dykes in Cornwall (like Bolster Bank though they are undated), Dane’s Dyke cutting off Flamborough Head (though that might be prehistoric) and Horning Dyke in Norfolk are all examples of dykes that cut peninsulas. Perhaps they just made a defensible small area where the locals could retreat to. Early medieval warfare probably involved a lot of intimidation, shouting, burning down of farms and chasing unarmed peasants, but when faced with a determined group of people on a large bank across an equally deep ditch, most raiders would probably go to where pickings were easier. The trouble is with this period is we can let our imagination run away with us, though I believe my theory about it being a period of frequent small-scale raids and dykes being “stop lines” dug by local farmers (and as other historians have said, moving earth is very much a peasant’s solution to a problem) is based on a sound analysis of all the evidence.
….my calculations suggest that with early medieval tools between 40 and 70 people could have built it over a Summer
High Dyke has suffered much in the past, not least through roadworks. I hope it is preserved and appreciated for future generations who will probably ask new questions, use different techniques and come to slightly different conclusions. Increasingly we are looking at features and asking how they fit into the wider landscape, just what was behind the High Dyke is likely to become a more important question to future researchers. Never forget that we never know what is under our feet and when we dig it must be done with care and carefully recorded for future generations, we can only excavate things once and who knows what new scientific techniques will be added to the archaeologist’s arsenal in the future.
- Grigg, E. (2018) Warfare, raiding and defence in Early Medieval Britain (2018) published by Robert Hale [The High Dyke is on page 182, but this book gives a general overview of the earthworks and my research]
- Roman Road. In the Proceedings of the Cambridge Antiquarian Society Volume 85 pp. 27-122 [This paper gives the best account on the Cambridgeshire Dykes, but frustratingly rarely mentions High Dyke, though it does on page 58]
- Malim, T., K. Penn, et al. (1996) “New Evidence on the Cambridgeshire Dykes and Worsted R.C.H.M.E. (1972). An Inventory of the historical monuments in the County of Cambridge, Volume 2 North-East Cambridgeshire. Published by Trinity Press. [Pages 144 to 147 give a good account of the dyke]