Donnchad Donn

Donnchad Donn (died 944), son of Flann Sinna of Clann Cholmáin, twice rebelled against his father, in 904 and 915. When his brother Conchobar and brother-in-law Niall Glúndub fell fighting the Vikings at Dublin in 919, Donnchad took Mide and the high kingship. He blinded one brother, Áed, and killed another, Domnall.

He long fought his son-in-law Muirchertach of the Leather Cloaks, who raided Mide in 941 and fell in 943. On his death in 944 his nephew Congalach Cnogba succeeded him as king of Tara.