Dictionary of National Biography, 1885-1900/O'Neill, Owen (1380?-1456)
O'NEILL, OWEN or EOGHAN (1380?–1456), Irish chieftain, probably born about 1380, was the eldest son of Niall Og O'Neill, chief of Cinel Eoghain, less correctly known as king of Tir-Eoghain or Tyrone, who was styled one of the four kings of Ireland, was knighted by Richard II in 1395, and died in 1402. In 1398 Owen slew Rory Maguire, and perhaps for this offence was next year a prisoner in Dublin Castle, when his father raised a large force, and threatened to ravage the Pale unless he were released. In 1410 Owen was engaged in war with his kinsman, Aedh Hugh O'Neill; in 1414 his brothers attacked Owen, and took him prisoner as a hostage for Donnell Boy O'Neill, ‘the O'Neill,’ and Owen's kinsman. He was soon afterwards released. In 1417 Owen O'Neill repulsed Talbot's attack on Eastern Ulster; but in 1419 war broke out between O'Neill and Donnell O'Neill; Owen sought alliance with his neighbours, the O'Donnells; a league was formed, and the allies marched into Tyrone, ‘the O'Neill's’ country, where, being joined by Brian MacMahon, ‘lord of Oriel’ (i.e. a portion of co. Louth), and Thomas Maguire, lord of Fermanagh, they ravaged the country, and expelled the O'Neill, who sought refuge with the English across the Bann. Peace was concluded the same year, but in 1420 Owen again drove the O'Neill into Sligo. In 1421 Owen was taken prisoner by Mac-i-Neill Boy, but was ransomed next year by his wife and sons; then, uniting with other chiefs, Owen plundered Carbery, and, marching against Mac-ui-Neill Boy, recovered more than the equivalent of his ransom. Next year he co-operated with the English in an attack upon Connaught, but in 1423 he turned against his new allies, and ravaged Louth in alliance with Magennis and MacMahon.
In 1425 O'Neill was captured by Sir John Talbot [q. v.] at Trim, and after imprisonment in Dublin Castle was ransomed. In order to protect settlers and the tenants of Richard, duke of York, on whom the earldom of Ulster had devolved, Ormonde in the same year entered into a compact with O'Neill. In an elaborate indenture, drawn up in Latin, and printed in the ‘Reports on the Records of Ireland, 1810–1815,’ pp. 54–56, Owen acknowledged the suzerainty of the king of England, and declared himself a tenant of the Duke of York; he covenanted that neither he nor his people would molest the English settlers or invade the lands of the earldom of Ulster, but would aid King Henry and the Duke of York in war and peace. But in 1430 he was again in open war, levying contributions on the Pale, plundering the settlements in the plains, and burning fortresses. Descending from Ulster on Longford and West Meath with other chiefs, he made war on the English settlers until they came to terms. In 1431 he attacked the MacQuillins, and maintained his army in their country for six weeks. In 1432, on the death of Donnell Boy O'Neill, Owen was inaugurated ‘O'Neill’ and chief of Cinel Eoghain. In 1435 he won the victory of Sliabh-truim (now the mountain Bessy Bell) over Brian Oge O'Neill and the Conallachs, and in 1443 he slew Emher MacMathghamhna (MacMahon). In the following year he again levied blackmail on the English settlers of the Pale and in Ulster, and John Mey [q. v.], archbishop of Armagh, was compelled to recognise his regal authority. In 1455, after further wars, he was deposed from the kingship of Tyrone, and banished by his eldest son, Henry, who was inaugurated the O'Neill in his stead. Owen died in the following year.
He married Catherine or Caitriona (d. 1427), daughter of Ardghal MacMahon, by whom he had numerous offspring, of whom Niall was killed in 1435. Henry [q. v.], the eldest, who became the O'Neill in 1455, is separately noticed.
[Annals of the Four Masters, passim; Annals of Loch Cé (Rolls Ser.), ii. 147–63; Hardiman's Statute of Kilkenny (Irish Archæol. Soc.), pp. 52–53; Gilbert's Viceroys of Ireland, pp. 292–354; O'Hart's Irish Pedigrees, ed. 1887, i. 719; Wright's Hist. of Ireland, i. 211–41; Lingard's Hist. of England, iii. 175; Burke's Extinct Peerage; Webb's Compendium of Irish Biography.]