The Annals of Ulster record that in April 1165, the Ulaid, ruled by Eochaidh Mac Dúinn Sléibe, turned against Muirchertach Mac Lochlainn, and attacked the Uí Méith as well as the Uí Breasail in modern barony Oneilland East, County Armagh (which was also formerly part of Ulaid), and the Dál Riata. In retaliation Mac Lochlainn led a force consisting of the Northern Uí Néill and Airgíalla into Ulaid killing many and expelling Eochaid from the kingship. In September Eochaid tried to reclaim the kingship, however was expelled by his own people who feared reprisals from Mac Lochlainn, upon whose command had Eochaid confined by Ua Cerbaill. The next month Mac Lochlainn led another raid into Ulaid, receiving their hostages along with a large amount of their treasure. Later that same month Ua Cerbaill along with Eochaid held a meeting with Mac Lochlainn where Eochaid requested the kingship of Ulaid in return for the hostages of all Ulaid, which included the son of every chief along with his own daughter. Eochaid also gave Mac Lochlainn a considerable amount of treasure along with the territory of Bairrche, and the townland of Saul. In turn, Mac Lochlainn swore an oath to the Bishop of Armagh amongst other nobles for his good behaviour. Mac Lochlainn then give Bairrche to Ua Cerbaill for his part in mediating what turned out to be short-lived reconciliation. Over the following century, the Airgíallan Mughdorna would settle Bairrche, and from them derives its present-day name of Mourne. Despite his oath, Muirchertach had Eochaid seized and blinded, after which his allies abandoned him, and he was reduced to a handful of followers. With sixteen of these closest associates, he was killed in 1166.