As our attention in dealing with the history of the seventh century will now be fixed chiefly on Northumbria, that being the region where Christianity won its most glorious victories and as it was at this time undoubtedly the predominant state in Britain, it is necessary at the cost of a little repetition to describe the course of the English settlements in that northern land. And first, a word as to its geographical limits. The district which was popularly called _Northhymbraland_, and which consisted politically of the two kingdoms of _Beornice_ (Bernicia) and _Dearnerice_ (Deira), stretched from the Firth of Forth to the river Humber. It is important to remember that we have here no concern with the medieval and modern boundary between England and Scotland, in which Tweed and Cheviot are the principal factors. St. Cuthbert, born on the slopes of the Lammermoor Hills, was no Scot but an Englishman; and Edinburgh, which is to us the very type and symbol of Scotticism, was in all probability founded by the English prince whose name stands at the head of this chapter. Between these two great natural frontiers, the Forth and the Humber, the bounding lines ran--as they still do, more than is generally recognised--north and south rather than east and west. The western half of the lowlands of Scotland, together with Westmorland and the greater part of Cumberland, formed the British kingdom of Strathclyde, and was--with the exception of some intervals of subjection to its Anglian neighbours--under the rule of kings of Celtic race, whose capital was the strong rock-fortress of Alclyde or Dumbarton. South of the kingdom of Strathclyde the high land which now sunders Yorkshire from Lancashire probably formed for some generations the boundary between the Angles and the Britons; yet not even up to that boundary was the Anglian dominion pushed in the first invasion, for we hear indistinctly of a British kingdom of Elmet, otherwise called Loidis, which probably included at any rate the upper part of the valleys of the Wharfe, the Aire and the Calder, all Yorkshire streams. As to the boundary between the two Anglian kingdoms of Bernicia and Deira we cannot speak with absolute certainty, but we are told on trustworthy authority[53] that it was the River Tees. The fact that both kingdoms were so often united under one sovereign perhaps made the assignment of precise boundaries less needful. Thus, to recapitulate these facts in terms of modern geography, Bernicia included probably all the three Lothians, the counties of Berwick, Peebles and Roxburgh, the eastern half of Northumberland and the county of Durham; while Deira claimed the North and East Ridings of Yorkshire.