[1] Kilcoursey barony is located in north County Offaly, south of the Gageborough River.

The Ó Sionnaigh (later Fox) O'Catharniagh (O'Carney) clan were chiefs in Kilcoursey, referred to as Muinter Tadgain, which also included Clonlonan barony in Westmeath.

In the early centuries of Christianity in Ireland, the family were known as O' Kearney, or Carney (in the Anglicized form), from their chief, Tadgh O'Catharniagh, who died in 1084.

The influence and power of the Foxes declined, due to conflict with rival Gaelic monarchs, and advancing control of English forces.

[2]The Mac Amhlaigh (MacAuley) sept are also cited as holding a portion of the Clonlonan barony.