Déisi

The Déisi were a social class in Ireland between the ancient and early medieval period. The various peoples listed under the heading déis shared a similar status in Gaelic Ireland, and had little or no actual kinship, though they were often thought of as genetically related. During the era of Roman rule in Britain, many members of the Déisi were recorded as settling in western coastal areas (especially the areas known later as Wales, Cornwall and Devon).

During the early Middle Ages, some Déisi groups and subgroups exerted great political influence in various parts of Ireland. For instance, in Munster, a subgroup of Déisi constituted a regional kingdom, Déisi Muman, and were part of the hegemony of the Eoganachta confederacy.