O'Connor Roe (Ó Conchobhair Ruadh), Feidhlimidh Fionn (d. 1490), lord of the O'Connor Roes, was seemingly eldest son of Tadhg O'Connor Roe (d. 1464). On the death of Aodh O'Connor Don (qv) on 15 May 1461, Tadhg was proclaimed king of Connacht by his own supporters. Unfortunately for him, he was quickly captured by his O'Connor Don rivals. This propelled Feidhlimidh Fionn to the leadership of his father's followers. Feidhlimidh was as unlucky as his father and was taken captive by Brian Ballach O'Connor and Ruaidhrí O'Connor Don (qv). However, he was not without friends. Shortly after his capture the MacWilliam Burkes came to his rescue, forcing the O'Connor Dons to set him free, and with the help of the Burkes he proudly proclaimed himself O'Connor Roe at a ceremony presided over by MacDermot of Magh Luirg. This audacity inflamed his kinsmen who still recognised the captive Tadhg as dynastic overlord. Indeed, they immediately began negotiations to obtain his freedom from the O'Connor Dons, giving them part of Cloontooskert, Co. Roscommon. Despite his venerable age, Tadhg and his sons quickly reasserted themselves, taking revenge on their rivals. In Easter 1462 they defeated the sons of Brian Ballach O'Connor, killing Diarmait Mór O'Connor at Boyle a year later. Throughout this period Feidhlimidh Fionn managed to avoid their ire, but he was wounded in an encounter with MacBrannan. In spite of this, he took MacBrannan and held him to ransom for a princely sum of four score marks. It was clear, though, that his pretensions to the O'Connor Roe leadership were not seriously countenanced by his kinsmen. Indeed, after Tadhg's death on 18 August 1464, it was Cathal Ruadh O'Connor Roe (d. 1465), son of Tadhg and brother of Feidhlimidh Fionn, who succeeded him. This succession as so often led to civil war, culminating in the killing of Cathal Ruadh on 30 March 1465. At this stage the O'Connor Dons spied their chance to exploit the weakness of their rivals, sparking a major war in east and central Connacht. In particular they concentrated their attacks on Feidhlimidh Fionn, forcing him and MacDermot of Magh Luirg to flee into the Curlew mountains. The revenge of Feidlimidh and MacDermot was swift: they appealed to the MacWilliam Burkes and linked up with them to burn Ballintober castle that year. This pattern of warfare was to continue. In 1467 the O'Connor Dons took the island of Ardkillin on Lough Cairrgin from Feidhlimidh Fionn. However, he deftly exploited the difficulties of the O'Connor Dons during the next year. That year he carried off hundreds of animals from the O'Connor Don lands and Magh Luirg before attacking Ballintober castle again, defeating the counter-attack with heavy casualties.
After raiding the lands of his O'Connor Roe kinsmen and rivals in autumn 1470, Feidhlimidh Fionn decided to make peace with them, leading to a period of prolonged dynastic stability. Indeed, the next mention of Feidhlimidh Fionn comes in 1487, when he travelled north to meet and make an alliance with the powerful Aodh Ruadh O'Donnell (qv) (d. 1505), while that year he and his four sons beat off an attack by Uilleag Burke (qv). In the resulting peace agreement (1487), lordship over several areas was given to Feidhlimidh Fionn. He finally succeeded in his ambition to become the undisputed O'Connor Roe leader, assuming the title on the death of Donnchadh Dubhsúileach (1488). Significantly, his inauguration was attended by the MacWilliam Burkes, the O'Donnells, and MacDermot of Magh Luirg. He died in the house of MacGeraghty (Mac Oireachtaigh) on Easter Monday 1490 and was succeeded by Ruaidhrí O'Connor Roe. Ruaidhrí (d. 1492) proved a short-lived king and was succeeded by Feidhlimidh Fionn's son Aodh O'Connor Roe (d. 1504). Nothing is recorded of his reign; he was succeeded on his death (1504) by his equally obscure brother Eóghan (d. 1519), of whose reign all that can be discerned is that he died in 1519.