With the opening of the seventh century substantial historic data begin. Ethelfrith, the last pagan king of Northumbria, crossed the southern end of the Pennine Chain in 603, and by a notable victory at Chester extended, as Bede tells us, the dominions of the English to the Mersey and the Dee. The actual conquest of Peakland probably soon followed. Mr. Grant Allen’s supposition that it was never actually overrun by a military force, but that the scanty numbers of the Welsh were by degrees absorbed into the surrounding English population, may, however, be the true explanation. The general story of English place-names shows that the majority of our hill and river names are earlier than the English occupation; but in North Derbyshire there is not a single river or hill that does not bear a Welsh name, whilst not a few of the homestead names have a like origin, and even words of Cymric etymology still linger in the fast disappearing dialect. It is of interest to remember that those Mercians who settled from time to time in small groups throughout the wilder parts of Derbyshire bore the local name of Pecsaete, that is to say, settlers in the Peak; so that the future county, as Mr. Allen remarks, narrowly escaped being styled Pecsetshire, after the fashion of Dorsetshire or Somersetshire. In the development and Christianising of the widespread Mercian kingdom, South Derbyshire played a very considerable part. Repton, on the banks of the Trent, is mentioned in the _Anglo-Saxon Chronicle_ in the year 755 in the account of the slaying of Ethelbald, the Mercian king. The same Chronicle also records the visit of the devastating Danes to Repton in 874, when they made that town their winter quarters. The founding of an abbey at Repton early in the seventh century, and the same place becoming the first seat of the Mercian bishopric from 654 to 667, is dealt with in another part of this volume and need not be named further in this sketch.