The Meic Lochlann, also spelt as Mic Lochlainn, and Mac Lochlainn, were a leading branch of the Cenél nEógain, who were in turn a segment of the Uí Néill. The Meic Lochlainn descended from Domnall Dabaill (died 915), son of Áed Findliath. Another son of the latter was Niall Glúndub eponymous ancestor of the Ua Néill. As a result of their descent from Domnall Dabaill, the Meic Lochlainn were known as Clann Domnaill or Clann Domhnaill. The eponym behind the surnames of the Meic Lochlainn—Mac Lochlainn, Ua Lochlainn, Ó Lochlainn—is Lochlann mac Máelsechnaill, King of Inishowen (died 1023). The surnames themselves formed not as a result of Lochlann's prominence, but as a consequence of the remarkable success of his grandson, Domnall Ua Lochlainn (died 1121).