 Máel Sechnaill was a grandson of Donnchad Midi mac Domnaill of Clann Cholmáin, who was King of Tara from around 778 to 797.Clann Cholmáin was a sept of the Uí Néill which ruled as Kings of Mide in east central Ireland.While the southern Uí Néill had been dominated by the Síl nÁedo Sláine Kings of Brega in the 7th and early 8th centuries, the Clann Cholmáin were dominant from the time of Máel Sechnaill's great-grandfather Domnall Midi.