 The Kingship of Tara, a largely symbolic title, alternated between Clann Cholmáin as representatives of the southern Uí Néill and the Cenél nEógain as representatives of the northern Uí Néill.Máel Sechnaill became king of Mide and head of Clann Cholmáin after killing his brother Flann in 845, and king of Tara in 846 on the death of Niall Caille mac Áeda of the Cenél nEógain, who drowned in the Callan River close to Armagh.He had appeared in the Irish annals some years earlier, being noticed in 839, and again 841 as a result of fighting among the chiefs of Clann Cholmáin when he killed his cousin Diarmait, son of Conchobar mac Donnchada, when Diarmait had tried to depose Máel Sechnaill's father as king of Mide.