Tadhg of Uí Díarmata
Tadhg mac Muircheartach was the first recorded king of Uí Díarmata, a local kingdom located in what is now north County Galway, Ireland, who died in 971. Background. Tadhg mac Muircheartach was a member of the Síl Muiredaig dynasty, who ruled as kings of The Connachta in what is now central County Roscommon. By the mid 10th-century they had expanded south-west into the north-east of County Galway. Here a branch of the kindred seized territory and renamed it Uí Díarmata, after its founder, Diarmada Finn mac Tomaltaig, who was in turn a great -grandson of King Indrechtach mac Muiredaig (died 723). Death and successors. Murchad Glun re Lar mac Flaithbertaigh, King of Ailech and King Cathal mac Tadg of Connacht fought each other at Ceis Corran in 971. Cathal was defeated and killed, along with many of his allies including: "Geibheannach, son of Aedh, lord of Ui-Maine; Tadhg, son of Muircheartach, chief of Ui-Diarmada; Murchadh, son of Flann, son of Glethneachan, chief of Clann-Murchadha; and Seirridh Ua Flaithbheartaigh, with a countless number along with them: and Murchadh totally plundered Connaught afterwards." His son, Concenaind mac Tadhg, though never apparently king  himself, would give his name to the ruling dynasty of Uí Díarmata, Ó Cú Ceanain (anglicised "Concannon")