Following the blow, he burned their villages and broke the castles of the stranger throughout Devlin, Calry, and Brawny, and replaced in power over them the McCoghlans, Magawleys, and O'Breens, from whom he took hostages according to ancient custom. Two years afterwards he repulsed Walter de Burgh at Shannon harbour, driving his men into the river, where many of them perished. At his death (A.D. 1283) he is eulogized for having destroyed seven-and-twenty English castles in his lifetime. From these exploits he was called Art _na Caislean_, a remarkable distinction, when we remember that the Irish were, up to this time, wholly unskilled in besieging such strongholds as the Norman engineers knew so well how to construct. His only rival in Meath in such meritorious works of destruction was Conor, son of Donnell, and O'Melaghlin of East-Meath, or _Bregia_, whose death is recorded at the year 1277, "as one of the three men in Ireland" whom the midland English most feared. From the ancient mensal the transition is easy to the north. The border-land of Breffni, whose chief was the first of the native nobles that perished by Norman perfidy, was at the beginning of the century swayed by Ulgarg O'Rourke. Of Ulgarg we know little, save that in the year 1231 he "died on his way to the river Jordan"—a not uncommon pilgrimage with the Irish of those days. Nial, son of Congal, succeeded, and about the middle of the century we find Breffni divided into two lordships, from the mountain of Slieve-an-eiran eastward, or Cavan, being given to Art, son of Cathal, and from the mountain westward, or Leitrim, to Donnell, son of Conor, son of Tiernan, de Lacy's victim. This subdivision conduced neither to the strengthening of its defenders nor to the satisfaction of O'Conor, under whose auspices it was made. Family feuds and household treasons were its natural results for two or three generations; in the midst of these broils two neighbouring families rose into greater importance, the O'Reillys in Cavan and the Maguires in Fermanagh. Still, strong in their lake and mountain region, the tribes of Breffni were comparatively unmolested by foreign enemies, while the stress of the northern battle fell upon the men of Tyrconnell and Tyrone, of Oriel and of the coast country, from Carlingford to the Causeway.