Here is a bit on Quinn from the Irish Times Ancestor Search
Quinn
Quinn is now one of the most numerous of Irish surnames, ranked 18th and 17th in 1890 and 1996 respectively, and is to be found in every county in Ireland. The name arose separately in five distinct areas. In four of these - near the modern town of Corofin in Co. Clare, in the glens of north Antrim, near Castlebar in Co. Mayo and in Co. Longford - the Irish original from which the surname derives is Ó Cuinn, from Conn, a popular personal name meaning "chief" or "leader". The family based in Clare were very prominent - the barony of Inchiquin bears their name. The first to use name was Niall Ó Cuinn, who fought and died in the army of Brian Ború at the battle of Clontarf in 1014. In early times they were chiefs of the Clan Heffernan, and their descendants are today Earls of Dunraven and Mountearl. Their seat was Adare Manor in Co. Limerick, now a hotel and golf course. The seventh Earl still lives nearby. The fifth area where the name originated is Tyrone; today Quinn is the most common surname in the county. The family were part of the Clann Feargusa, descendants of Fergus, grandson of Niall of the Nine Hostages, the fifth-century monarch who founded the dynasty of the Uí Néill. The individual from whom descent is claimed was Coínne, a grandson of Fergus. All of the Clann Feargusa were conspicuous In the fighting forces of the O'Neills..
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