The Kings of Ailech belonged to the Northern Uí Néill and were based at the Grianan of Aileach (Irish: Grianán Ailigh), a hillfort on top of Greenan Mountain in modern-day County Donegal, Republic of Ireland. The restored fort stands in a commanding position at the base of the Inishowen peninsula overlooking Lough Swilly to the west and Lough Foyle to the east.
Earlier Kings of Cenél nEógain and Ailech included:
The following is a list of their Kings from 700 to 1185. Some were also High Kings of Ireland.
The last to actually be styled King of Ailech was Áed Buide Ua Néill (died 1283).