Local man’s new book offers fresh look at Black Pig’s Dyke

(Above) An artist's impression of the Black Pig's Dyke.

A north Westmeath archaeologist has just published a new book on one of the most enigmatic and neglected of all of Ireland’s prehistoric field monuments, the Black Pig’s Dyke in County Monaghan.

Co-authored by Castlepollard’s Aidan Walsh, ‘Materialising Power – The Archaeology of the Black Pig’s Dyke’, offers a fresh perspective on the mysterious linear earthworks that are found in around 12 locations in the north midlands and south Ulster, including a section just outside Granard.

The name the Black Pig’s Dyke originates from a folk tale that describes how the earthworks were torn into the landscape by the angry marauding of a giant mythical schoolteacher-turned-pig. The 10-kilometre stretch in Monaghan is one of the best-preserved and largest examples of this type of ancient monument in Europe.

Aidan’s association with the Black Pig’s Dyke in Monaghan dates to 1982, when he led the first excavation on it at Aghareagh West while he was the curator of the award-winning Monaghan County Museum.

In their richly illustrated publication, Aidan and his co-author Cóilín Ó Drisceoil (director of the Black Pig’s Dyke Regional Project) integrate the results of excavations undertaken by Aidan almost 40 years ago with new surveys and scientific dating to present a radical reassessment of the chronological and physical development of the monument and its environmental and archaeological setting.

Speaking to the Westmeath Examiner, Aidan revealed that the use of new technologies had led to a number of exciting discoveries.

(Above) Aidan Walsh.

“I found interesting finds and information [in 1982] but we didn’t publish the full details [until the publication of this book].

“I have all of the archive and the images but I also lodged all of the original charcoal samples that we collected. I lodged them in the County Museum in Monaghan and we were able to go in and reanalyse them.

“The extraordinary thing was the amount of information we were able to get out of them because of the advances in technology. For instance, I had a date on the construction of the dyke between 500 and zero BC, which was all that I could get because of the technology at the time. We had sent charcoal to both The Netherlands and to Queens in Belfast and neither were able to get a more precise date.

“However, this time we went and got the samples from the museum in Monaghan. When we reanalysed them we got a date of around 100BC. We tied it down tightly. We also discovered that part of the dyke was actually built 1,000 years earlier. There must have been an earlier phase.

“I had found charcoal in the body of the monument, in the bank itself, but we had so little at the time in the ‘80s that they said we wouldn’t get a date out of it. The new technology allowed us to get a date for the piece of charcoal, which we thought may have been a hearth, to around 1600BC. It means that the earthwork which we thought was constructed around the time of Christ or a bit before had an earlier life.

“We now also have information telling us that it was destroyed in the first century AD.”

The new research also disproved the theory that the earthworks were some sort of Irish replicas of Roman structures such as Hadrian’s Wall in the north of England.

“When these earthworks were first looked at around 1900 and discussed by various scholars, they all had a strong belief that they were Irish copies of Roman walls. When I was in college that’s what I was told.

“However, the Roman walls post-dated the earthworks. They were built after the Irish earthworks.”

The publication of the book was the catalyst for a number of other archaeologically significant discoveries using the latest technology.

“We decided to look at the fields either side of the earthwork where I did the dig to see if there was anything that might give us further information.

“Amazingly, a Bronze Age village turned up under the grass. What’s different to the old days is that it was completely non-invasive work, no excavation. It was all using these new techniques of ground radar and geophysical techniques which identify remains in the ground. It showed that there were round huts there, that there were pits there, basically that the dyke was built over or near a village that was much older than it, of course.

“Without modern technology we wouldn’t have been able to advance our information about the dates or anything like that,” Aidan says.

While recent technological advances have provided more pieces to the puzzle, there is still much debate about why the earthworks were constructed in the first place. One theory put forward by some members of the Unionist community in Northern Ireland is that the Black Pig’s Dyke was an ancient “Great Wall of Ulster” that existed to separate the province from the rest of the island. However, Aidan and other archaeologists say that there is no evidence to back that theory up.

“The fact that similar earthworks are found in Longford and Westmeath and in Cork and other parts of Ireland indicate that they were not simply a border,” Aidan says.

It is now thought that while they were used as a boundary of sorts, they were also an expression of status or power by the Celtic elites behind their construction. The reasons such ancient earthworks were built and subsequently destroyed remain a mystery to modern scholars, though.

“We still have lots of questions we can’t answer. What really was it used for? It was a huge construction and its construction would have occupied a huge number of men. Huge numbers of trees would have had to have been cut down to make the fence on the top of it. Then why was it totally destroyed, burned down?

“I found the evidence on the ground, the trench that this fence had been set in to. It was virtually a metre deep and 90cm wide. It was chock-a-block with charcoal. The whole fence had been burned and I found this at a couple of different points along the 10km stretch. What were they doing? We can’t answer all those things.”