A series of four parallel earthworks cut the line of the Icknield Way south east and south west of Cambridge. They are up to 5 miles long and up to 34 feet high. Most people have never heard of them.
The Wansdyke is a linear earthwork which stretches from Marlborough to Bath, with some interruptions. That is a distance of about 40 miles. In places it is about 20 feet high. Most people are completely unaware of its existence.
In the 1860s and 1870s the Victorian antiquarian General Augustus Pitt Rivers excavated a number of long linear earthworks in East Yorkshire. They were generally known as the Wolds Entrenchments. Pitt Rivers’ conclusion was that they were built by a people expanding westwards from the area near the coast, fortifying as they went. The Wolds Entrenchments are generally forgotten today, yet there are dozens of them. They are easy to find, run for miles, and are typically several feet high.
Pitt Rivers also excavated a major earthwork astride the Roman road between Salisbury and Blandford Forum, about two miles from the Chalke Valley. Called the Bokerly (or Bokerley) Ditch, it is about 12 feet high in places today. There is a car park where the A354 crosses it. Occasionally, curious tourists wander over it and wonder who built it. But the great majority of people have never heard of it.
Pitt Rivers considered that the Bokerley Dyke and the Wansdyke (which he also excavated) were late or post-Roman defence works. There are hundreds of these earthworks. They are spread across much of England (but very little of Scotland or Wales). In total they are hundreds of miles long.
They would have taken hundreds of thousands, if not millions, of man-hours to build. Very few have been excavated. The most famous is Offa’s Dyke, excavated over eight seasons in the 1920s and 30s by Sir Cyril Fox. The few that have been dated with any rigor have been shown to be late- or post-Roman. In the 1960s the chief archaeologist of the Ordnance Survey considered them to be ‘[t]he most impressive monuments of the Dark Ages in Britain’. Yet today they are almost entirely forgotten.
These Dark Age dykes raise four key issues. The first is to find out how many there are, where they are, and how big they are. The other three issues should be applied to each earthwork in turn: ‘who built it?’, ‘why did they build it?’ and finally ‘why did they build it there?’ (‘there’ in the sense of locally, regionally and nationally). If you do that, you come to some interesting conclusions. I shall be talking about my findings at this year’s Chalke Valley History Festival.