15. =Eadwine's Conversion and Fall.=--In =627= Eadwine, moved by his wife's entreaties and the urgency of her chaplain, Paulinus, called upon his Witan to accept Christianity. Coifi, the priest, declared that he had long served his gods for naught, and would try a change of masters. 'The present life of man, O king,' said a thegn, 'seems to me in comparison of that time which is unknown to us like to the swift flight of a sparrow through the room wherein you sit at supper in winter, with your ealdormen and thegns, and a good fire in the midst, and storms of rain and snow without.... So this life of man appears for a short space, but of what went before or what is to follow we are utterly ignorant. If therefore this new doctrine contains something more certain, it seems justly to deserve to be followed.' On this recommendation Christianity was accepted. Paulinus was acknowledged as Bishop of York. The new See, which had been originally intended by Pope Gregory to be an archbishopric, was ultimately acknowledged as such, but as yet it was but a missionary station. Paulinus converted thousands in Deira, but the men of Bernicia were unaffected by his pleadings. Christianity, like the extension of all better teaching, brought at first not peace but the sword. The new religion was contemptible in the eyes of warriors. The supremacy of Eadwine was shaken. The men of East Anglia slew their king, who had followed his over-lord's example by accepting Christianity. The worst blow came from Mercia. Hitherto it had been only a little state on the Welsh border. Its king, Penda, the stoutest warrior of his day, now gathered under him all the central states, and founded a new Mercia which stretched from the Severn to the Fens. He first turned on the West Saxons, defeated them at Cirencester, and in =628= brought the territory of the Hwiccas under Mercian sway. On the other hand, East Anglia accepted Eadwine's supremacy and Christianity. Penda called to his aid Caedwalla, the king of Gwynnedd, the Snowdonian region of Wales. That he should have done so shows how completely AEthelfrith's victory at Chester, by cutting the Kymric realm in two, had put an end to all fears that the Kymry could ever make head against England as a whole. The alliance was too strong for Eadwine, and in =633=, at the battle of Heathfield--the modern Hatfield, in Yorkshire--the great king was slain and his army routed. 16. =Oswald's Victory at Heavenfield.=--Penda was content to split up Bernicia and Deira into separate kingdoms, and to join East Anglia to his subject states. Caedwalla had all the wrongs of his race to avenge. He remained in North-humberland burning and destroying till =635=, when Oswald, who was a son of AEthelfrith and of Eadwine's sister, and therefore united the claims of the rival families, gathered the men of Bernicia round him, overthrew Caedwalla at Heavenfield, near the Roman Wall, and was gratefully accepted as king by the whole of North-humberland.