The monastery and cells of St. Ciaran rapidly grew into a city, to which students flocked from far and near. In one sense the College of Clonmacnois had an advantage over all its rivals, for it belonged to no one race or clan. Its abbots and teachers were drawn from many different tribes, and situated as it was, in almost the centre of the island, all the great races, Erimonians, Eberians, Irians, and Ithians, resorted to it impartially, and it became a real university. There the O'Conors, kings of Connacht, had their own separate church; there the Southern Ui Neill reared apart their own cathedral; there the MacDermots, princes of Moylurg, and the O'Kellys, kings of Hy Mainy, had each their own mortuary chapels; there the Southerns built one round tower, the O'Rorkes another; and there too the Mac Carthys of Munster had a burial-place. Who, even at this day, has not heard of the glories of Clonmacnois, of its ruins, its graves, its crosses; of its churchyard, which possesses a greater variety of sculptured and decorated stones than perhaps all the rest of Ireland put together, and of which the Irish poet beautifully sang so long ago-- "In a quiet watered land, a land of roses, Stands St. Ciaran's city fair, And the warriors of Erin in their famous generations, Slumber there. There beneath the dewy hill-side sleep the noblest Of the clan of Conn, Each below his stone, with name in branching Ogham, And the sacred knot thereon. There they laid to rest the seven kings of Tara, There the sons of Cairbré sleep, Battle-banners of the Gael that in Ciaran's Plain of Crosses, Now their final hosting keep. And in Clonmacnois they laid the men of Teffia, And right many a lord of Breagh. Deep the sod above Clan Creidé and Clan Conaill, Kind in hall and fierce in fray. Many and many a son of Conn the Hundred-Fighter In the red earth lies at rest, Many a blue eye of Clan Colman the turf covers, Many a swan-white breast."[17] Some of the most distinguished scholars of Ireland, if not of Europe, were educated at Clonmacnois, including Alcuin, the most learned man at the French court, who remembered his alma mater so affectionately that he extracted from King Charles of France a gift of fifty shekels of silver, to which he added fifty more of his own, and sent them to the brotherhood of Clonmacnois as a gift, with a quantity of olive oil for the Irish bishops. His affectionate letter to "his blessed master and pious father" Colgan, chief professor at Clonmacnois, is still extant.