Rather than sinuous or straight, in many places Offa’s Dyke is built of short straight segments. In their recent book Offa’s Dyke: Landscape and Hegemony in Eighth-Century Britain, Ray and Bapty identify a series of places where this distinctive form of construction is in evidence. They call this ‘adjusted-segmented construction’ made of ‘straight alignments’ rather than meandering to follow the topography. In their words, ‘adjusted segmented construction’ is:

the effect of creating a string of segments that could either be built as single links or grouped together in approximate multiples to produce a chain.

Contrasting with Cyril Fox’s view who saw the behaviour of the dyke as relating to the impedence of land-use and vegetation, Ray and Bapty not only identify this phenomenon in various locations, they propose it was a deliberate design feature of the monument with strategic intent.

Dudston Fields, Chirbury (Shropshire/Powys border) is the only location where the detail of the dyke’s surviving bank and ditch have been recorded by Royal Commission (RCAHMWE) field survey in sufficient detail to work out the identification of 3 dimensions to the ‘adjusted-segmented construction’:

  1. shorter sections of dyke with straight alignments of usually between 20m and 80m,
  2. how these short sections interconnect, with tapering overlaps to the bank-ends overlap at their ends, and
  3. how these sections relate to subtle alignment shifts of over 100m or more as the dyke seemingly navigates the landscape.

Further examples of this phenomena, albeit not mapped to the same level of detail, are identified by Ray and Bapty elsewhere, significantly both on valley slopes and as the Dyke works its way around hillsides at:

  1. Discoed, Powys (p.199-201)
  2. Spoad, near Newcastle-upon-Clun, Shropshire (p. 201-203)
  3. Bronygarth, near Chirk, Wrexham (p. 203)
  4. Llanfair Hill, Shropshire (p. 203) (part of a wider stretch from Spoad to Garbett Hall;
  5. Fron Farm, Gwenfro, Wrexham (identified based on a photograph by Fox in his survey of the dyke: p. 205);
  6. Rushock Hill to Herrock Hill, Herefordshire (p. 206)
  7. Devil’s Pulpit, Gloucestershire (p. 206-7).

This last example is particularly significant for it is integral to Ray and Bapty’s argument that the Gloucestershire sections of the dyke are of similar build (and therefore presumably date) as those farther north: i.e. that this was indeed part of Offa’s Dyke rather than a separate work of different date and function (contra Hill and Worthington 2003).

The sweeping line of Offa’s Dyke looking south as it navigates around the western edge of Hawthorn Hill, south of Knighton, Powys. Superficially sinuous at a glance…
Offa’s Dyke on the southern slope of Hawthorn Hill, looking south. Superficially it looks sinuous…

Why? Ray and Bapty propose that this design feature coincides with places where the Dyke enjoys a wider prospect. The ‘adjusted-segmented construction’ was perhaps to ‘bulk out’ the dyke, and they assert that it was a ‘thoroughly designed manipulation’:


Perhaps the reason for this (quite possibly functionally needless) elaboration may have served, like the pattern-welding of the most prestigious among Anglo-Saxon swords, to express a particular aesthetic: in this case, for the joy of a continuous facetted form in the performance of a built work (p. 204-5).

Regardless of the reasoning, this observation and its careful articulation are one of the highlights of Ray and Bapty’s book, and their text work to good effect to give a sense of this phenomenon in basic terms. As they admit, few sections of Offa’s Dyke have received systematic survey (a shocking realisation for me on reading their book) and therefore the ‘case’ they put isn’t fully articulated in map form. Even Ray and Bapty’s photographs don’t fully reveal the character of the phenomenon, which might spread seeds of doubt in those unfamiliar with the monument. Still, their photographs of sections at Panpunton Hill (Figure 5.20, p. 191), Garbett Hall (Figure 5.21, p. 193), Llanfair Hill (Fig. 5.37, p. 211) and Discoed (Fig. 6.6, p. 230) as well as those accompanying the text on pages 203-9 do help to build the case.

Having been introduced to this feature in the field at Dudston Fields by Keith Ray, I’ve been keen to ‘test out’ whether I believe it on the ground elsewhere. Hence, I’m keen to present a further striking case of this phenomenon that is presumably known to Ray and Bapty but doesn’t receive specific mention in their book. I’m refering to a stretch of Offa’s Dyke on Hawthorn Hill south of Knighton, Powys. In low evening sunlight, I recently got to walk this section as the dyke navigates prominent hills with striking wide views to the west.

A similar view to the last, but with a clear sense that the earthwork is ‘facetted’

To my mind, the superficially sinuous course is easily broken up and individiaul straight segments can be discerned. While I couldn’t conclusively see them overlap as Ray and Bapty recognise at Dudston Fields, and while I couldn’t measure the distances of the stretches, I would provisionally propose that some are of the c. 20-80m range Ray and Bapty identify.


Looking north on Hawthorn Hill, the ‘adjusted-segemented’ design is apparent

One of the remaining questions of Ray and Bapty’s work is the extent to which this phenomenon is widespread or indeed universal. They are cautious, stating that:

The adjusted-segmented build practice is not to be found everywhere, but it nonetheless can be observed throughout the course of the Dyke.

This begs the question: where can it be demonstrably shown not to be deployed? Where does the dyke effectively meander following topography or run near-straight against the topography? This is a key question for future research.

Looking south along the Dyke at Hawthorn Hill
Looking south as Offa’s Dyke mounts Hawthorn Hill

Likewise, it is important to rule out, or rule in, the presence of this design feature on other early medieval linear earthworks, not only those of western Britain such as Wat’s Dyke, but those elsewhere, such as East Anglia and Wessex. Is this simply a universal of dyke construction, or something ‘special’ about Offa’s Dyke?


Whether this design feature has aesthetic motivations, is a fossilation of how the dyke was built with gangs working on set distances, and/or perhaps is part of a way of working to make the Dyke emulate Roman linear frontier works – i.e. the Antonine Wall and Hadrian’s Wall – further research is desperately required on this phenomenon.

Looking north along the Dyke at Hawthorn Hill
Looking north along Offa’s Dyke on Hawkthorn Hill