The ancestral lands of the O'Shaughnessy sept were in Kinelea (Cineál Aoidh), a district that was co-extensive with the diocese of Kilmacduagh, centered around the town of Gort, Co Galway.176

The 'Annals of the Four Masters' state the John, the son of Gilladuff (Sir Roger) was nominated O'Shaughnessy. This John O'Shaughnessy the eldest son of Sir Roger, was born before the Lady Honora O'Brien, his mother, was married, in Galway; still it would appear that the Government were inclined at one time to acknowledge him as chief of his sept, although they had before given their decision in favour of his uncle Dermot Riveagh. In 1585 this John and his younger brother Dermot attended Perrot's Parliament. Thus it would seem the Government of that unfortunate period endeavoured to make the O'Shaughnessy clan quarrel among themselves by having two of its members to represent it at the same time. John, finding that the laws of England were in favour of his younger brother Dermot--who had made efforts to depose him--conveyed the lands of Cineal Aodh to Sir Geoffry Fenton 'for the sole consideration of Sir Geffrie maintaining his title against Dermod.' On Fenton's death Sir Fulco Comerford, who was son of Gerald Comerfod of Incholegan in Kilkenny, Baron of the Exchequer in 1603, claimed all Cineal Aodh under his will.177