Dyke may not just be Offa’s as history slowly unearthed
Offa’s Dyke could actually be four centuries older than previously thought. Will Hayward explains why this could change the history of Wales and England
Archaeologists at a Welsh castle have just completed a dig that could change how we view one of Britain’s most wellknown medieval monuments. Offa’s Dyke is a large earthwork that roughly follows Wales’ border with England and is named after the AngloSaxon king of Mercia, Offa, who ruled from AD 757 until 796.
In the past it was assumed that it was Offa who had ordered the construction, but recent discoveries have cast doubt on that assumption. Members of the Clwyd-Powys Archaeological Trust have excavated part of the dyke at Chirk Castle, in Wrexham, in a rare opportunity to find out more about it. According to archaeologist Ian Grant, who leads the team, the reason this opportunity is so unique is down to the protected status of much of the dyke. He said: “It is all part of the project Linear Earthworks in Wales, which is funded by Cadw jointly by the National Trust. It specifically targets Offa’s Dyke and the lesser-known Wat’s Dyke.
“Offa’s Dyke goes through Chirk Castle and Wat’s Dyke goes through Erddig Hall, near Wrexham.
“Both dykes have many questions that need to be posed about them.
“Because the National Trust is involved this is a real opportunity. We as archaeologists get funding and the National Trust volunteers get trained in archaeological techniques.
“We excavated in the estate grounds to the north of the castle. It is an area of the dyke which is unprotected. It is not protected because it was largely flattened in the 18th century as it was near a high-status property. It may have been flattened to open up the view.
“Archaeologists don’t really get a chance to excavate Offa’s Dyke because most of it is a protected national monument. It has been decades since we have been given permission.”
According to Ian, it is not the dyke itself they are excavating, but the ditch in front of it. Back over a millennium ago there was a nasty surprise in that ditch for people trying to cross it.
“The dyke was mainly built using earth from the ditch, although some sections will have come from quarries,” he said.
“We excavated the ditch, which is not something to take on lightheartedly.
“It is six metres wide and three metres deep, with a very steep ‘ankle-breaking trough’ at the base.
“One of the things we see, even in Roman times, is a very narrow and steep trough about twice the width of the spade. This would have to be maintained and added an extra hindrance to people crossing the ditch.”
Things like the trough pose questions that the team are looking to answer.
“The trough raises questions as to what it was intended for.
“The dyke was one construction and intended for one use, but as local situations and politics changed, did the use change in specific areas?
“The million-dollar question is, was it one dynasty that built it or was it ongoing over a longer period of time spanning two or three kings?
“Other excavations have suggested it straddled Offa’s reign. That was established through radiocarbon dating.
“We are not suggesting we are going to change history, but there are questions that need answering.”
The team’s two-week excavation has just finished and they now face a long wait while the data is analysed in the lab.
“It is finished for the time being,” said Ian.
“What we have got now is to take all the samples from the bottom of the ditch and what we believe to be the base of the dyke.
“If you are looking to date an earthwork you want to use the material at the base.
“We are sampling charcoal and radiocarbon-dating it. We should have results in the late spring next year. The excavation of Wat’s Dyke earlier in the year was just as successful.”