under the Ulster branch of the de Burgh dynasty (other branches of this kinship group held territories elsewhere in Ireland, but became heavily Gaelicised). The Bruce campaign in Ireland, with the defenders of the Anglo-aligned Lordship of Ireland being led by Richard Óg de Burgh, 2nd Earl of Ulster, suffered significantly during the conflict. Eventually the Norman title to the Earldom of Ulster passed to the Mortimer family. Niall Mór O'Neill, King of Tyrone (1364–1397) created a vacuum in the area by driving out some of the Anglo-Norman settlers. The Kingship of Tyrone had in recent times been contested by two sets of cousins, one of which was the Clandeboye O'Neills (descended from Hugh Boy O'Neill), who had provided three Kings of Tyrone in the 13th century, before losing out to the line descended from Aodh Reamhair O'Neill (son of Domhnall O'Neill), whom all subsequent Tyrone kings would descend from. By 1347, Muirchertach Ceannfada O'Neill was the first King of Clandeboye not to be also King of Tyrone, controlling the parts of the old Earldom of Ulster taken over by the O'Neills. Most of their territory was east of the River Bann, in what would today be called south County Antrim and north County Down. The part of Clandeboye territory which was west of the River Bann was Loughinsholin, in what is today County Londonderry, including part of the Sperrin Mountains. This O'Neill line, which had lost out on the Kingship of Tyrone, although technically at first uirrithe (under-kings) of their Tyrone cousins, soon established their own autonomy. Geopolitically, they looked to offset the power of their Tyrone neighbours, by forming alliances with other powers in the area; the MacDonnells of Antrim (a clan of fairly recent Highland Scots descent), the powerful O'Donnells of Tyrconnell and, when it suited, the Kingdom of England's Lordship of Ireland based in Dublin. Clandeboye's lands were suited to cattle grazing and so their rulers were able to attain a significant level of wealth through this. 15th century: shifting alliances Towards the end of the 14th century and into the early 15th century, the Clandeboye shifted away from their rapprochement with their O'Neill of Tyrone cousins and as with the case of their neighbours to the south, the Magennis clan of Iveagh, entered into an alliance with the powerful O'Donnells of Tyrconnell under Turlough an Fhíona O'Donnell (1380—1422). An ascendant maritime kingdom based in the