Hugh Boy O'Neill (Irish: Aed Buide Ó Néill) was the last ruler of the Cenél nEógain to be styled as king of Ailech and was the eponymous ancestor of the Clandeboye O'Neill's in medieval Ireland.[1] The son of Donnell Og O'Neill, he succeeded to the kingship of Ailech after the death of Brian O'Neill at the battle of Down in 1260. His name in English translates as "Blonde Hugh" on account of his hair colour giving rise to the English alias Hugh the Blond or Hugh the Fair.