more severe defeat on him, and he was again defeated by a lesser chief, O'Maeldoraigh, in 1051. He had before held as a prisoner Amhalghaidh O'Flaherty, king of West Connaught, whom he blinded in this year, and secured himself from his foes of East Connaught at Inis Creamha, on the east side of Loch Orbsen. He thence made an expedition against the Conmaicne, a tribe situated near Slieve Formaeile, co. Roscommon, and an expedition into Clare, when he cut down the tree of assembly of the O'Briens at Moyre, then called Aenach Maighe Adhair. He again plundered the Conmaicne in 1052, and Clare in 1054 and 1059, when he received the submission of the chief of the O'Briens. In 1061 he is first mentioned by his cognomen, no explanation of which is given in the best known chronicles. He sacked Cenncoradh, O'Brien's fortress on the Shannon, and burnt the neighbouring town of Killaloe. Solitary trout in wells or isolated pools are still regarded with veneration by the Irish in remote parts, and in 1061 O'Brien had two salmon in the well of Cenncoradh, which, by way of insult, O'Connor caught and ate. While he was on the Shannon, O'Flaherty attacked and destroyed his stronghold on Loch Orbsen; but when O'Connor returned he routed the O'Flahertys, slew their chief, and carried his head to Rathcroghan in Roscommon. In the next year he defeated the Clan Coscraigh, a tribe settled to the east of Galway Bay. In 1063 Ardgar MacLochlainn, king of Ailech, invaded Connaught, and both O'Connor and his rival O'Rourke were obliged to give him hostages and admit his supremacy. O'Connor had hidden his treasure and jewels in the cave of Aille in the parish of Aghagower, co. Mayo; but his old enemies, the Conmaicne, slew the guard and sacked the cave; but in 1065 he defeated them and their allies, the Ui Maine, under Tadhg O'Kelly, at Clonfert, and killed O'Kelly's sons and grandson some time after the battle. He soon after defeated and slew Duarcan O'Heolusa, chief of Muinter Eoluis, co. Leitrim. In 1066 he was concerned in the murder of the heir of O'Muiregain, chief of Teffia, co. Westmeath, a connection by marriage of his own, and it was perhaps in consequence of this outrage that he was attacked in 1067 by Dermot, son of Maelnambo, king of Leinster, and by the O'Briens. He had some success at first, and slew O'Connor Kerry; but in a battle near Oranmore, co. Galway, in which he was attacked by O'Rourke, he and many of his followers were slain. In a verse which preserves the date he is called ‘rí Connacht,’ king of Connaught, and he was undoubtedly the heir to that kingship, but exercised its rights without dispute for a very short part of his life, and never seems to have received the formal submission of all Connaught. He had five sons—Murchadh, slain in 1070; Roderic or Ruaidhri [q. v.] ‘na soighe buidh,’ or ‘of the yellow hound,’ who became king of Connaught, and died in 1118; Cathal; Tadhg, slain in 1062 by Aedh O'Flaherty; Aedh, who had two sons, Cathal and Tadhg—and one daughter, Aoibhean, who married O'Muiregain, and died in 1066.
[Annala Rioghachta Eireann, ed. O'Donovan, vol. ii.; Genealogies, Tribes, and Customs of Hy Fiachrach, ed. O'Donovan, Dublin, 1844; Tribes and Customs of Hy-Many, ed. O'Donovan, Dublin, 1843; A Chorographical Description of West or H-Iar Connaught, by Roderic O'Flaherty, ed. Hardiman, Dublin, 1846.]
O'CONNOR, ARTHUR (1763–1852), Irish rebel, was born on 4 July 1763 at Mitchelstown, co. Cork, of a well-to-do protestant family. His father, Roger Connor, was a large landed proprietor. His mother was Anne, daughter of Robert Longfield, M.P. (1688–1765), and sister of Richard Longfield, created Viscount Longueville in 1800. Roger O'Connor [q. v.] was his brother. Arthur, after attending schools near Lismore and at Castlelyons, entered Trinity College, Dublin, in 1779, as a fellow-commoner, under the name of Connor, and graduated B.A. in 1782. In Michaelmas term 1788 he was called to the Irish bar, but never attempted to practise. In 1791 his uncle, Richard Longfield, afterwards Lord Longueville, whose heir he was, procured him a seat in the Irish parliament as member for Philipstown. The French revolution had turned O'Connor into a republican. In parliament he manifested very liberal sentiments, and strongly supported the catholics. He declared that his views were well known to his uncle, and were not resented by him. After an eloquent speech in the house on 4 May 1795, in which he strongly supported the catholic claims, he resigned his seat. It is improbably said that Pitt was so impressed by O'Connor's oration that he offered him an important government post (Madden, United Irishmen, ii. 233).
In 1796 O'Connor joined the ‘United Irishmen,’ but took no oath, and, with Lord Edward Fitzgerald, formed the first ‘Leinster Directory.’ In February 1797 he was arrested on a charge of seditious libel, and was imprisoned for six months in Dublin Castle. On his release he became chief editor of the newly started ‘Press,’ the organ of the United Irishmen, and he was appointed one
