Henry Aimreidh O'Neill
O'Neill, Henry Aimreidh, entitled "The Contentious," by antiphrasis, from his peaceable disposition, was son of Niall Mor, and founder of the Clann-Enri, who in the 14th century settled in and about the present town of Newtownstewart, in the County of Tyrone, where he is still remembered as Henry Ouree. O'Donovan says: "There are more traditions preserved about this Henry Avry O'Neill than any of the later chieftains of that family, excepting, perhaps, Owen Roe and Sir Phelim."
Sources
134. Four Masters, Annals of Ireland by the: Translated and Edited by John O'Donovan. 7 vols. Dublin, 1856.