The Expulsion of the Déisi

The Expulsion of the Déisi is a medieval Irish narrative of the Cycles of the Kings. It dates approximately to the 8th century, but survives only in manuscripts of a much later date. It describes the fictional history of the Déisi, a group that had gained political power in parts of Ireland during the Early Middle Ages. Part of the text's purpose is to provide the kings of the Déisi – historically the descendants of unlanded vassals to other tribes – with a mythical noble origin as the heirs to a dynasty expelled from Tara.