Etched across the landscape of much of Ireland and Britain are lengths of banks and ditches bearing evocative names like the Scot’s Dyke, Grim’s Ditch, the Claidh Dubh (translated as “the Black Wall”) and the Dane’s Cast. Archaeologists prefer to describe them as ‘linear earthworks’ (or sometimes ‘travelling earthworks’, ‘dykes’ or ‘ranch boundaries’), and it is in Britain and Ireland that the most extensive and oldest examples of in Europe are to be found.
Around a dozen individual linear earthworks that occur across the width of the north midlands and south Ulster have been grouped together as ‘the Black Pig’s Dyke’. This name comes from a folk tradition that the earthworks were torn into the landscape by the angry marauding of a giant mystical school-teacher-turned-pig.
Another, somewhat fantastical, its interpretation which developed in the early 20th century is that it is the remains of a once-unified territorial boundary for Ulster, ‘the Great Wall of Ulidia’, suggesting that the people of Ulster were ‘always’ culturally separate and distinct from the rest of the Irish. As time and research has gone on, this explanation is looking less and less likely. Nevertheless, this fusion of myth and politics has attracted writers like James Joyce (Finnegan’s Wake), W.B. Yeats (The Valley of the Black Pig) and Vincent Woods (At the Black Pig’s Dyke), all of whom have imagined the dyke as a symbol of the complexities of the Irish identity.
Although linear monuments are amongst the largest, most fascinating and last monumental constructions of the prehistoric period, they have been largely overlooked by modern Irish archaeology. Just six linear earthworks have been excavated in Ireland at:
- the Claidh Dubh, Co. Cork
- the Knockans, Co. Meath
- the Rathduff trench, Co. Kilkenny;
- the Black Pig’s Race at Aghareagh West; Co. Monaghan,
- the Dorsey, Co. Armagh,
- Magheracar, Co. Donegal.
As a result, these earthworks are poorly understood, and even the number of prehistoric linear earthworks in Ireland is unknown, contributing to their mystery.
Of all the Irish linear earthworks, those that are said to form the Black Pig’s Dyke are amongst the most extensive and best preserved. Since 2014 they have been the subject of an ongoing multidisciplinary research project that aims to shed light on these unanswered questions; this website is a part of that project.