The death of his brother and of Malachy within the same year, proved favourable to the ambition of Donogh O'Brien. All Munster submitted to his sway; Connaught was among the first to recognise his title as Ard-Righ. Ossory and Leinster, though unwillingly, gave in their adhesion. But Meath refused to recognise him, and placed its government in commission, in the hands of Con O'Lochan, the arch-poet, and Corcran, the priest, already more than once mentioned. The country, north of Meath, obeyed Flaherty O'Neil, of Aileach, whose ambition, as well as that of all his house, was to restore the northern supremacy, which had continued unbroken, from the fourth to the ninth century. This Flaherty was a vigorous, able, and pious Prince, who held stoutly on to the northern half-kingdom. In the year 1030 he made the frequent but adventurous pilgrimage to Rome, from which he is called, in the pedigree of his house, _an Trostain_, or the cross-bearer. The greatest obstacle, however, to the complete ascendency of Donogh, arose in the person of his nephew, now advanced to manhood. Thorlogh O'Brien possessed much of the courage and ability of his grandfather, and he had at his side, a faithful and powerful ally in his foster-father, Dermid, of Leinster. Rightly or wrongly, on proof or on suspicion, he regarded his uncle as his father's murderer, and he pursued his vengeance with a skill and constancy worthy of _Hamlet_. At the time of his father's death, he was a mere lad—in his fourteenth year. But, as he grew older, he accompanied his foster-father in all his expeditions, and rapidly acquired a soldier's fame. By marriage with Dervorgoil, daughter of the Lord of Ossory, he strengthened his influence at the most necessary point; and what, with so good a cause and such fast friends as he made in exile, his success against his uncle is little to be wondered at. Leinster and Ossory, which had temporarily submitted to Donogh's claim, soon found good pretexts for refusing him tribute, and a border war, marked by all the usual atrocities, raged for several successive seasons. The contest, is relieved, however, of its purely civil character, by the capture of Waterford, still Danish, in 1037, and of Dublin, in 1051. On this occasion, Dermid, of Leinster, bestowed the city on his son Morrogh (grandfather of Strongbow's ally), to whom the remnant of its inhabitants, as well as their kinsmen in Man, submitted for the time with what grace they could.