Eóganacht Chaisil was a significant dynasty in early medieval Ireland, primarily associated with the region of Munster. This royal family claimed descent from Eógan, a legendary figure, and played a crucial role in the political landscape of the time. They were known for their influence over the Kerry and Limerick areas, and their power peaked during the 8th and 9th centuries. The dynasty is often linked to the establishment of several important ecclesiastical sites, including Cashel, which served as a major center of power. The Eóganacht Chaisil were involved in various conflicts and alliances with other dynasties, such as the Eóganacht Glendamnach and the Uí Néill, shaping the history of Ireland during their reign.