The victory by the Winwaed left Oswy undoubtedly the mightiest king in Britain. It may be convenient to enumerate here the chief territorial changes during the latter half of the seventh century which can be discerned between the succession of bishops and the miracles of saints that form naturally the chief subject of Bede’s _Ecclesiastical History_. 1. Northumbria, at any rate after Oswy’s victory, may have stretched along the eastern coast from Aberdeen or the Cromarty Firth nearly to the Wash. We are distinctly told that “he subdued the nation of the Picts or at least the largest part of them to the Anglian kingdom,” and it is generally agreed that this must refer to the Picts north of the Firth of Forth, which was at this time the ordinary Anglian boundary. Southward, the dominions of which Oswy was overlord probably now included the whole of Yorkshire. It seems, however, to have been an accepted principle that when the overlord was king in Bernicia there must be an under-king in Deira. For seven years, as we have seen, the comely and gracious Oswin, either as equal colleague or as such under-king, reigned in Deira (644–51). After his murder and the consequent extinction of the direct male line of the descendants of Aelle, Oswald’s son, Ethelwald, ruled over the southern kingdom. Did his dubious conduct on the battle-plain of the Winwaed fail to secure for him the favour of his victorious uncle? We cannot say, but it is an ominous circumstance that soon after that event he vanishes from the scene and is replaced by Alchfrid, son of Oswy by his first marriage. We have heard of this prince as assisting in the conversion of his brother-in-law, Peada, to Christianity; we have seen him fighting by his father’s side against his father-in-law, Penda; we shall find him taking a leading part in the discussions about the date of Easter and generally befriending the Roman party; but besides these facts we hear also of some action on his part, possibly in the way of overt rebellion, whereby he added to the “labours” of his father. Whatever the date of this rebellion, if such it were, after 664 we hear no more of Alchfrid.