The Déisi were a socially powerful class of peoples from Ireland that settled in Wales and western England between the ancient and early medieval period. 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. 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. During early medieval Munster, the Déisi were under the hegemony of the Eoganachta confederacy. Etymology Déisi is an Old Irish term that is derives from the word déis, which meant in its original sense a "vassal" or "subject", a designated group of people who were rent-payers to a landowner. Later, it became a proper noun for certain septs and their own subjects throughout Ireland. 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. 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). Today, 'Déisi' is an informal term for County Waterford and its people. Déisi Muman The Déisi Muman were a prominent enough power to form their own regional kingdom in Munster from a fairly early date. In a recent title, Paul MacCotter states "The regional kingdom of Déisi Muman must have existed in roughly its present location from a very early period. Oghams dating perhaps from the fifth century record unique first names associated with its kings." According to Francis John Byrne, there are certain inscriptional hints that both the Eóganachta and their Waterford Déisi vassals may have been of fairly recent Gaulish origins. The ancestors of the Eóganachta are known as the Deirgtine and they are also believed to have been