The
Eóganachta or
Eoghanachta were an Irish dynasty centred on
Cashel which dominated southern
Ireland from the 6/7th to the 10th centuries, and following that, in a restricted form, the
Kingdom of Desmond, and its offshoot
Carbery, to the late 16th century. By tradition the dynasty was founded by
Conall Corc but named after his ancestor
Éogan, the firstborn son of the semi-mythological 3rd-century king
Ailill Aulom. This dynastic clan-name, for it was never in any sense a 'surname,' should more accurately be restricted to those branches of the royal house which descended from Conall Corc, who established Cashel as his royal seat in the late 5th century.