Déisi

The Déisi were a class of peoples in ancient and medieval Ireland. The term is Old Irish, and derives from the word déis, meaning "vassal" or "subject"; in its original sense, it designated groups who were vassals or rent-payers to a landowner. Later, it became a proper name for certain septs and their own subjects throughout Ireland. The various peoples listed under the heading déis shared the same status in Gaelic Ireland, and had little or no actual kinship, though they were often thought of as genetically related. Déisi groups included the Déisi Muman (the Déisi of Munster), Déisi Temro (of Tara), Déisi Becc (located in the Kingdom of Mide) and the Déisi Tuisceart (the Northern Déisi; a sept of which would become famous as the Dál gCais). During the Early Middle Ages some Déisi groups and subgroups exerted great political influence in various parts of Ireland, and certain written sources suggest a connection to Britain as well.

History and contexts

The early histories of the Déisi groups are obscure. As a class that evolved from peoples tied by social status rather than kinship, groups had largely independent histories in different parts of Ireland. While some medieval texts attempt to give the Déisi an aristocratic origin, these are later fabrications dating to the period after the Déisi had gained political power. Despite their tributary origins, representatives of at least one Déisi population would eventually achieve spectacular success, founding a powerful medieval dynasty which is still in existence.