gains in this part of today’s Co. Tyrone, as well as elsewhere through his northern kingdom.47 He also established a firm alliance “between the House of York and the O’Neills, which lasted for several generations and aided the race of Niall Mor (Eoghan’s grandfather) in establishing an hereditary succession which lasted to the end of the next century”, and right up till the English Conquest.48
Art O’Neill was probably born around the turn of the fourteenth century, and was raiding into Fermanagh by 1426, while his wife, Mor Maguire, died in 1449.49 Sometime in those years he built the first stone castle at Omagh, near the spot where the Camowen and Drumragh rivers join to meet the Strule.50 His brother, ousted his father, King Eoghan, in 1455, to be King of Ulster. 51 Art died in 1458. His descendants can be traced through the next two centuries. For here, between Omagh and the Derg river, they had carved out a chiefdom for themselves, which later became today’s barony of Omagh.52
The York-O’Neill agreement of 1449 was cemented by the marriage of Eoghan’s grandson (and Art’s nephew). Conn Mor O’Neill, to Eleanor, sister of Lord Deputy Garret Mor Fitgerald (who twice laid siege to Omagh castle) – an alliance that proved too strong for the Slioclit Airt combination which included even the great O’Donnell, the first Red Hugh, Lord of Tir Conaill, whose sister, Sheila, was married to Art’s son, Niall of Omagh. 53
Under the Gaelic brehon law the chieftainship of the sept was open in theory to all the capable male descendants of a common great-grandfather chieftain.54 We find then that the struggle of Sliocht Airt to produce a king of Ulster was at its bitterest under Art’s grandsons, the great grandsons of King Eoghan himself. For this was the last generation of Art’s line that could legally be eligible for the title of The O’Neill. But they failed twice in that generation against the ruling line of Conn Mor’s sons – Art Og, king from 1513 to 1519, and his brother, Conn Bacach (1519-’59), the first Earl of Tyrone.55 During the bitterest part of this domestic O’Neil war, we find the Sliocht Airt, so often on the defensive, retiring here to the wooded shelter of this secluded, quiet country between Omagh and the Derg, which they made their own. It is marked on the early maps as “Slught Art” territory and included this parish as well. 56 There were raids and counter-raids between the two warring groups of O’Neills. Omagh Castle was razed to the ground in 1509 by Fitzgerald, who rushed up from the south again to the aid of his sister’s stepson,
47 “Ceart Ui Neill” in Leabhar Cloinne Aodh Buidhe (ed. Dr. T. O. Donnchadha, Baile Atha Cliath, 1931), leath. 34.
48 E. Curtis, A History of Ireland (London 6th Ed., 1950), p. 139
50 AU. Map of Omagh in the Escheated counties, 1609, shows clearly the remains of O’Neills old castle at this spot.
52 Ibid. Cf. CR (1970), 262; My Old Fintona (Monaghan 1974), pp. 16-18
54 Eoin MacNeill, Celtic Ireland (Dublin 1921), chapter viii; “The Law of Dynastic Succession”.
55 Old Fintona, 17-18.
56 Cf. Map of 1609, marking the territory of “Slught Art” often confused with “Sliocht Airt Olg” (the stock of Art Og O’Neill, King of Ulster (1513-19). Cf. Dr. S. O. Ceallaigh’s identification of Sliocht Airt’s country in Anal. Gib. 3, p. 56.