[1] The date of his birth is not known, but he was apparently an adult in 904 when he is found as the leader, or figurehead, of a challenge to his father at Kells.
On Donnchad's death, he was succeeded as King of Tara by his sister's son, Congalach Cnogba, a member of the Síl nÁedo Sláine branch of the Uí Néill.
His first wife was Cainnech ingen Canannán (died 929), daughter of the King of the northern Uí Néill sept of the Cenél Conaill.
Órlaith was killed in 941, apparently on Donnchad's order, perhaps due to a sexual relationship between her and her stepson Óengus.
Donnchad's third wife, Dub Lémna ingen Tighearnáin (died in 943), was the daughter of the king of Bréifne.