Derry's medieval round tower rediscovered by local historians in grounds of Lumen Christi

Scientific dating by QUB researcher, Dr Gerard Barrett, of mortar samples from what was hitherto thought to be the stump of a 17th century windmill tower in the grounds of Lumen Christi College has now returned medieval radiocarbon dates that fall within 13th and 14th centuries AD, suggesting that this is actually the remains of a “lost” round tower.

In Irish, a round tower is called a cloigtheach, which translates as “bell house”, and it is thought that hand bells would have been rung from their top windows to mark the times of religious services each day in a Medieval monastery. The height of these tall taping towers - up to 35 metres in some cases - would also have meant that they could act as markers on the landscape that would be visible to travellers.

In addition, they were symbols of a monastic community’s power and affluence. As such, it is not to be unexpected that the monastic community in Derry (Doire Choluim Chille, “the Oakgrove of Colmcille”, named after its traditional founder, St Colmcille) would have had a round tower, given the importance of the monastery in the north-west of Ireland. Some 90 round towers, constructed between the 10th and 13th centuries AD, are known across Ireland, with 15 examples in Ulster, of which nine survive as stumps but the examples at Devenish Island (County Fermanagh) and the Steeple in Antrim (County Antrim) remain in pristine condition and demonstrate just how impressive these structures are.

The new scientific dates have been welcomed by the Derry Tower Heritage Group (DTHG) whose members have been studying the history of the tower for the last five years. The old monastic round tower was still standing in c. 1600 since it is shown on an English map of that time, and it was also depicted in a second English map, dated to c. 1625. By 1685, however, the round tower is no longer shown on a map of that year, but a windmill is shown on the outskirts of the city. There was a tradition, however, recorded in 1802 that the windmill had been constructed using the stump of the round tower for the mill tower. This tradition, however, was then overtaken by an academic consensus that the round tower - or the “Long Tower”, as it was known locally - had stood where the Roman Catholic church of that name is now located, but that it had been demolished.

A scheduled monument, the tower is located within a fenced area in the grounds of the school and, in 2013, it received conservation work from the Northern Ireland Environment Agency, now the Historic Environment Division of the Department for Communities. During this work, Stephen Doherty (a member of the DTHG and a teacher at Lumen Christi College) had the presence of mind to ask the contractors if they would collect a sample of the mortar for him from within the wall of the structure. This proved a far-sighted action. During the archaeological excavation undertaken on the lawn at the front of the college in 2017 by the Centre for Archaeological Fieldwork (CAF) at QUB, Stephen raised the work of his group with myself and I subsequently brought the mortar sample to Dr Gerard Barrett in the 14CHRONO laboratory at Queen’s who he knew to be working on the radiocarbon dating of mortar.

Dr Barrett explains the significance of the new dates: “What we have here are radiocarbon dates of medieval date from the fabric of a building. The obvious implication of this is that the building itself is of medieval date. Then, when we look at the work that the local historians have been doing, it’s pretty convincing that this is the general location of a medieval round tower. And when we look at the form of that tower we see that it has convincing similarities to the stumps of other round towers that survive across Ireland. The radiocarbon dates are not saying that the structure wasn’t reused as a windmill in the 17th century, but it would seem that the 17th-century builders were making-do and mending, using the stump of the old round tower for a new purpose.”

The new discovery is set to change our understanding of the early history of Derry. “The history books will certainly need to be revised”, says Stephen Doherty, of the DTHG. “Up to now we had no upstanding medieval fabric surviving in our city. Now we have a round tower.”

More info: www.derrytowerheritagegroup.com; email: [email protected];facebook: derrytowerheritagegroup