More than 150 years elapsed between the battle of Clontarf and the landing of the first Anglo-Norman, and they were years of almost constant war and confusion. Had Ireland been left to herself a prince might in time have arisen strong enough to establish such a monarchy as Brian failed to found. The Danes had ceased to be a seriously disturbing influence, but there is no evidence that any such process of consolidation was going on, and a feudal system, which had lost none of its vigour, was at last confronted with a tribal system which had lost none of its inherent weakness. [Sidenote: Progress of Christianity.] It is impossible to fix the exact date when Christianity began to make head against the Irish Ostmen. When St. Anschar obtained from the Swedes a place for his God in the northern pantheon, and when Guthrum and his officers submitted to baptism in Wessex, a foundation had been laid for a general Scandinavian conversion. But neither Norway nor the Norwegian colonies in Iceland, Shetland, Orkney, or the Hebrides, yielded so soon. Irish anchorites spent some time in Iceland about 795, and when Ingulf and Lief landed in 870 they found that Irish priests had lately been there, and had left behind them books, bells, and croziers. The second batch had probably fled from Ingulf's congeners in Ireland. Olaf Trygvesson, the first Christian king of Norway, was educated at Athelstane's court, and the nominal conversion of Norway may date from the year of his accession. Five years later, in 1000, Christianity was established by law in Iceland. Removed as she was from English or Roman influences, Ireland remained a stronghold of paganism after the Danes of England had been generally converted; and the Irish being on the whole weaker in war, were scarcely in a position to prove that Woden and Thor had nothing to say for themselves. Olaf Cuaran was baptized in England. It is clear that the Irish Danes remained generally pagan throughout the tenth century, and that the confederacy which failed at Clontarf had to a great extent been formed against Christianity. The story of Ospak and Brodir shows that some of the fiercest Danes were beginning to waver, the question at issue being the relative power of two deities, rather than the relative merit of two systems. After Clontarf Woden seems to have been looked upon as beaten. He had been tried and found wanting, like Baal on Mount Carmel, and the defeated party went over to the stronger side. [Sidenote: The Danish church of Dublin.]