Ferta – the term is preserved as an element in Irish place-names like Clonfert, Ardfert and at least a dozen other examples. A Ferta is a burial site which was used to mark boundaries and stake a tribe’s ancestral claim to the land. Archaeology research demonstrates burials to be boundary markers as they occur on hilltops, on spurs over rivers, on ravines overlooking large expanses of countryside or on known boundaries. Furthermore it is known from the large corpus of early medieval genealogies, laws, sagas and topographical sources that graves were used to mark boundaries and a large number of graves are included in the medieval Irish corpus of topographical poems and prose texts known as Dindshenchas Érenn ‘the place-lore of Ireland’.
Anthropological evidence universally recognises that burial rites were not only used as indicators of cultural identity but also of authority over a territory. In early Irish sources, especially in the laws and in saints’ lives, the legal process of taking possession of land involves the ability to cross and use the ferta or ancestral graves. This places burials at the heart of acquiring authority in early Ireland and may often explain the location of certain burials.
Extract from “Mapping Death: People, Boundaries and Territories in Ireland 1st – 8th Centuries AD” Full paper available: http://www.docstoc.com/docs/130343167/Untitled—The-Heritage-Council