It will be remembered that St. Patrick's first church was built on land given him by Dicu, chieftain of the district round Downpatrick, a name which commemorates the presence of the Messenger. Two sons of this same Dicu had been held as hostages by Laogaire the king, and their marvelous escape from durance was recorded in the name, Dun-da-lath-glas, the Dwelling of the Two Broken Fetters, given to Downpatrick. The place was of old renown. Known to Ptolemy as Dunum, it was, during Concobar's sway at Emain of Maca, the fortress of the strong chief, Celtcar, whose huge embattled hill of earth still rises formidable over the Quoyle River. In the year 823, we read, Dundalathglas was plundered by the Gentiles; but the story does not stop here, for we are further told that these same Gentiles were beaten by the Ulad armies not far from the great fort of Celtcar. This is the first entry of this tenor. Hitherto, the Northmen seem to have fallen only on outlying religious communities, in remote islands or on the seashore; but this last raid brought them to one of the very few church-schools which had been built close to a strong fortress, with the result that the Northmen were beaten and driven back into their ships. Three years later the Gentiles plundered Lusk on the mainland opposite Lambay, but in that same year they were twice defeated in battle, once by Cairbré son of Catal, and once by the king of Ulad. The raids of the Norse warriors grow more frequent and determined from this time; in itself a testimony to the wealth and prosperity of the country, the abundance of gold and of accumulated riches, whether cattle or corn, ornaments or richly dyed stuffs, red and purple and blue. Word seems to have been carried to the wild hills and fiords of frozen Scandinavia that here was booty in abundance, and the pirate hordes came down in swarms.