The victory of Chester divided the Welsh power in the north as that of Deorham had divided it in the south. Henceforward, the Northumbrians bore rule from sea to sea, from the mouth of the Humber to the mouths of the Mersey and the Dee. Æthelfrith even kept up a rude navy in the Irish Sea. Thus the Welsh nationality was broken up into three separate and weak divisions–Strathclyde in the north, Wales in the centre, and Damnonia, or Cornwall, in the south. Against these three fragments the English presented an unbroken and aggressive front, Northumbria standing over against Strathclyde, Mercia steadily pushing its way along the upper valley of the Severn against North Wales, and Wessex advancing in the south against South Wales and the West Welsh of Somerset, Devon, and Cornwall. Thus the conquest of the interior was practically complete. There still remained, it is true, the subjugation of the west; but the west was brought under the English over-lordship by slow degrees, and in a very different manner from the east and the south coast, or even the central belt. Cornwall finally yielded under Æthelstan; Strathclyde was gradually absorbed by the English in the south and the Scottish kingdom on the north; and the last remnant of Wales only succumbed to the intruders under the rule of the Angevin Edward I. There were, in fact, three epochs of English extension in Britain. The first epoch was one of colonisation on the coasts and along the valleys of the eastward rivers. The second epoch was one of conquest and partial settlement in the central plateau and the westward basins. The third epoch was one of merely political subjugation in the western mountain regions. The proofs of these assertions we must examine at length in the succeeding chapter. CHAPTER VII. THE NATURE AND EXTENT OF THE ENGLISH SETTLEMENT. It has been usual to represent the English conquest of South-eastern Britain as an absolute change of race throughout the greater part of our island. The Anglo-Saxons, it is commonly believed, came to England and the Lowlands of Scotland in overpowering numbers, and actually exterminated or drove into the rugged west the native Celts. The population of the whole country south of Forth and Clyde is supposed to be now, and to have been ever since the conquest, purely Teutonic or Scandinavian in blood, save only in Wales, Cornwall, and, perhaps, Cumberland and Galloway. But of late years this belief has met with strenuous opposition from several able scholars; and though many of our greatest historians still uphold the Teutonic theory, with certain modifications and admissions, there are, nevertheless, good reasons which may lead us to believe that a large proportion of the Celts were spared as tillers of the soil, and that Celtic blood may yet be found abundantly even in the most Teutonic portions of England.