Within the Roman Empire the centres of the Church had been the cities. Cities were the seats of its bishoprics. The models of its organization were urban. But in Ireland there were no cities. The episcopate was irregular and weak, denoting rank rather than authority or jurisdiction. The life of the Church was monastic and missionary. The weird Round Towers, believed to have been places of refuge for its ministers and their sacred vessels, as well as bell-towers, speak of a life surrounded by barbarism and rapine as well as threatened by the heathen and devastating Northmen. Partly perhaps owing to its comparative isolation and detachment at home, the Irish clergy was fired with a marvellous and almost preternatural zeal for the propagation of the Gospel abroad. It crossed the sea to Iona, the sacred isle, still to religious memory sacred, from which the light of the Gospel shone to the wild islesmen and to the rovers of the Northern Sea. Irish missionaries preached to heathen Germany, colliding there, it seems, with a more regular episcopate. They played a part in the conversion of Britain not less important than that of the missionaries of Rome, before whose authority, however, the Irish Church in the person of Aidan was at last compelled to retire, the decisive struggle taking place on the mode of celebrating Easter. In Ireland itself there arose in connection with the Church a precocious and romantic passion for learning which founded primitive universities. Its memory lingers in the melancholy ruins of Clonmacnoise. This was the delusive brightness of a brief day, to be followed by the darkness of a long night. The Church of Ireland seems in its origin to have been national and neither child nor vassal of Rome. Its theology must have been independent if Scotus Erigena was its son. But Rome gradually cast her spell, in time she extended her authority, over it. Its heads looked to her as the central support of the interests of their order and as their protectress against the rude encroachments of the native chiefs. Norman Archbishops of Canterbury served as transmitters of the influence. Still, the Irish Church was not in Roman eyes perfectly regular. Tithes were not paid, nor was the rule of consanguinity observed, or the rite of baptism administered in strict accordance with the ordinances of Rome. Christianity did not kill the brood of a lively superstition, the fairy, the banshee, the spectre, charms, amulets, prophecies, wild legends, which in the times of gloom that followed strengthened their hold upon Irish imagination.