 According to the books of Lecan and Ballymote, the Síl Ciarain Uí Echach were located in Airthir.The Uí Echach descend from Echach the grandson of Fiachra Cassán.The Uí Nialláin, or Clan Cernaich, descend from Nialláin, son of Féicc, son of Feidelmid, who was the son of Fiachra Cassán.