Flaherty O'Neill
O'Neill, Flaherty, Lord of Aileach, on the shores of Lough Swilly, was the first prominent member of the O'Neill family whose name appears in history, ruling his territory from 1004 to 1036. O'Donovan, cited by O'Mahony, says: "The Ui Neill, or the descendants of the monarch Niall of the Nine Hostages, were divided into two great branches, namely, the southern and northern. The southern Ui Neill were kings of Meath, and many of them monarchs of Ireland. The northern Ui Neill, of which there were two great branches, namely, the race of Eogan, princes of Tyrone, and the race of Conel, princes of Tirconnell, also furnished many monarchs of Ireland; but the descendants of Eogan were the most celebrated of all Milesian clans; of them a great many were kings of Ulster, and sixteen were monarchs of Ireland. The race of Eogan took the name of O'Neill in the 10th century, from Nial Ghmdubh (Black Knee), who was killed in a great battle with the Danes, near Dublin, A.D. 919. The elder branch of the O'Neill took the name of O'Lochlainn, and MacLoughlin, from Lochlainn, one of their ancient chiefs. The O'Neills afterwards recovered the supremacy, and made a distinguished figure in Irish history, down to the 17th century, as princes of Tyrone and kings of Ulster. The O'Neills had their chief seat at Dungannon, and were inaugurated as princes of Tyrone at Tullaghoge palace, between Grange and Donaghenry, in the parish of Desertcreight, barony of Dungannon, where a rude seat of large stones served them as a coronation chair." The Four Masters record fourteen plundering expeditions led by Flaherty into different parts of Ireland, both against his countrymen and the Northmen. He is sometimes called "Flaithbheartach an Trostain" — (Flaherty of the Pilgrim's Staff), from a pilgrimage he made to Rome. He was slain in 1036.
Sources
121. Edgeworth de Firmont, Memoires de M. l'Abbé: C. Sneyd Edgeworth. Paris, 1815.
134. Four Masters, Annals of Ireland by the: Translated and Edited by John O'Donovan. 7 vols. Dublin, 1856.