 In 823 Murchad's failures led to his deposition by his second cousin Niall Caille (died 846).Murchad seems to have accepted his fate and he is last heard of cooperating with Niall in routing out the Vikings in Daire Calgaig (Derry) in 833.Murchad may have had a Norse wife and the genealogies name Erulb as his son which corresponds to old Norse "Herulfr".