Although Owen Roe O'Neill possessed the qualities of a general, the struggle dragged on inconclusively for three or four years. In March 1646 a cessation of hostilities was arranged between Ormonde and the Catholics; and O'Neill, furnished with supplies by the papal nuncio, Rinuccini, turned against the Scottish parliamentary army under Major-General Robert Monro, who had been operating with fluctuating success in Ireland since April 1642. On 5 June 1646 O'Neill utterly routed Monro at Benburb, on the Blackwater; but, being summoned to the south by Rinuccini, he failed to take advantage of the victory, and suffered Monro to remain unmolested at Carrickfergus.
For the next two years confusion reigned supreme among the numerous factions in Ireland, O'Neill supporting the party led by Rinuccini, though continuing to profess loyalty to Ormonde as the king of England's representative. Isolated by the departure of the papal nuncio from Ireland in February 1649, he made overtures for alliance to Ormonde, and afterwards with success to Monck, who had superseded Monro in command of the parliamentarians in the north. O'Neill's chief need was supplies for his forces, and failing to obtain them from Monck he turned once more to Ormonde and the Catholic confederates, with whom he prepared to co-operate more earnestly when Cromwell's arrival in Ireland in August 1649 brought the Catholic party face to face with serious danger. Before, however, anything was accomplished by this combination, Owen Roe died on 6 November 1649.
Original text from Encyclopaedia Britannica 1911