Mellifont was founded in 1142, and richly endowed by O'Carrol, Prince of Oriel. He was famed for his generosity and piety. The establishment was built for the Order of Cistercians. From the middle of the eleventh century to the middle of the twelfth was the time when most of the large abbeys and monasteries of Ireland were founded; and many of them, like that of Cong, were built in places that had long been occupied by smaller and plainer ecclesiastical structures like those remaining in Clonmacnois and Monasterboice. The _renaissance_ of Irish ecclesiastical architecture in the eleventh and twelfth centuries is, probably, attributable to two things--the cessation of Danish plundering and the conquest of England by the Norman-French. The Danish military power in Ireland got a blow at Clontarf from which it never recovered; after that battle there were comparatively few monasteries raided, and the Irish began to erect large and costly structures in place of the small and often severely plain churches of an earlier period. The Norman-French introduced into England what is called a Romanesque ecclesiastical architecture that was much superior to that of the Saxons; and it seems certain that the Irish copied, to a certain extent, the style of building adopted by the conquerors of the Saxons; but the invasion of Ireland by those same conquerors in the latter half of the twelfth century seems to have arrested the development, not only of architecture, but of almost everything that tended to benefit the country. Most of the great churches and abbeys of Ireland were erected before Strongbow set foot in it. It is strange and hard to be understood how it came to pass that, terrible as were the ravages of the Danes, they put no stop to the development of Art in Ireland. Monasteries would be raided and churches burned by them many times within a few years, but this seems not to have put a stop either to the establishment of monasteries or the building of churches. Lord Dunraven says, in his book on ancient Irish architecture, that "it is remarkable that the fearful struggle with the Norsemen, which lasted for over two hundred years, and ended in their final defeat in 1014 [at Clontarf] does not seem to have materially paralysed the energies of the Irish nation as regards their native arts." It is, however, certain that it was not until the military power of the Norseman was broken that ecclesiastical architecture became a real glory in Ireland. But the Anglo-French invasion seems to have put a stop, not only to the development of architecture, but of art of all kinds. It is a strange fact that the heathen Dane should have been less of a curse to Irish art than the Christian Englishman.