Last of the English realms was established the great midland state of Mercia—the "March" or borderland. It was formed by the combination of three or four Anglian war-bands, who must have cut their way into the heart of Britain up the line of the Trent. Among these bodies of adventurers were the Lindiswaras—the troop who had won the old Roman city of Lindum, or Lincoln,—the Mid-Angles of Leicester, and the Mercians strictly so-called, who held the foremost line of advance against the Celts in the modern counties of Derby and Stafford. The Britons still maintained themselves at Deva and Uriconium (Chester and Wroxeter), two ancient Roman strongholds, and the Mercians had not yet reached the Severn at any point.
The Britons in the west.
About 570, therefore, after a hundred and twenty years of hard fighting, the Angles and Saxons had conquered about one-half of Britain, but they were stopped by a line of hills and forests running down the centre of the island, and did not yet touch the western sea at any point. Behind this barrier dwelt the unsubdued Britons, who were styled by the English the "Welsh," or "foreigners," though they called themselves the Kymry, or "comrades." They were, now as always, divided into several kingdoms whose chiefs were perpetually at war, and failed most lamentably to support each other against the English invader. The most important of these kingdoms were Cumbria in the north, between the Clyde and Ribble, Gwynedd in North Wales, and Damnonia in Devon and Cornwall. Now and again prominent chiefs from one or other of these three realms succeeded in forcing their neighbours to combine against the Saxon enemy, and styled themselves lords of all the Britons, but the title was precarious and illusory. The Celts could never learn union or wisdom.
LIMIT OF THE ENGLISH CONQUESTS,
About A.D. 570.
Battle of Deorham, 577.
The line of the British defence was at last broken in two points, and the Saxons and Angles pushed through till they touched the Irish Sea and the Bristol Channel. The first of the conquerors of Western Britain was Ceawlin, king of Wessex. After winning the southern midlands by a victory at Bedford in 571 he pushed along the upper Thames, and attacked the Welsh of the lower Severn. At a great battle fought at Deorham, in Gloucestershire, in 577, he slew the kings of Glevum, Corinium, and Aquae Sulis (Gloucester, Cirencester, and Bath). All their realms fell into his hands, and so the West Saxons won their way to the Severn and the Bristol Channel, and cut off the Celts of Damnonia from the Celts of South Wales.
Battle of Chester, 613.