ABSTRACT
Dál Cais was the name of the Munster people based in eastern County Clare that rose to prominence in the latter half of the tenth century and produced a number of powerful kings, including Brian Boru. Although they claimed kinship with the Eóganachta, who had dominated the province since the dawn of history, the Dál Cáis actually belonged to the larger population of Munster Déisi, who were ethnically Érainn. This Déisi population originally formed a loose conglomerate stretching from southern Waterford into Limerick, but by the eighth century, they had divided into two separate groups—the Déisi Muman of Waterford and southern Tipperary, and the western Déisi of Limerick. In the latter territory were the Déis Deiscirt, who were eventually eclipsed by their neighbors, and the Déis Tuais-cirt, who later changed their name to Dál Cais. Although legend has it that they conquered their lands in eastern County Clare from Connacht in the fifth century, historical sources suggest that they did not actually gain possession of this territory until the early eighth.
