Tadhg Caech Ó Cellaigh, King of Ui Maine, retired 1476.
Upon the death of Aedh na gCailleach Ó Cellaigh in 1469, the Ui Maine elected two kings, ruling Iar Ui Maine (west) and Airthir Ui Maine (east) respectively. They were Tadhg Caech Ó Cellaigh of Airthir, and William in the west. Upon the retirement of Tadhg in 1476, Uilliam became king of all Ui Maine, installing his brother, Donnchadh, as tainiste in Airthir.