The history of our dialects in the earliest periods of which we have any record is necessarily somewhat obscure, owing to the scarcity of the documents that have come down to us. The earliest of these have been carefully collected and printed in one volume by Dr Sweet, entitled _The Oldest English Texts_, edited for the Early English Text Society in 1885. Here we already find the existence of no less than four dialects, which have been called by the names of Northumbrian, Mercian, Wessex (or Anglo-Saxon), and Kentish. These correspond, respectively, though not quite exactly, to what we may roughly call Northern, Midland, Southern, and Kentish. Whether the limits of these dialects were always the same from the earliest times, we cannot tell; probably not, when the unsettled state of the country is considered, in the days when repeated invasions of the Danes and Norsemen necessitated constant efforts to repel them. It is therefore sufficient to define the areas covered by these dialects in quite a rough way. We may regard the Northumbrian or Northern as the dialect or group of dialects spoken to the north of the river Humber, as the name implies; the Wessex or Southern, as the dialect or group of dialects spoken to the south of the river Thames; the Kentish as being peculiar to Kent; and the Mercian as in use in the Midland districts, chiefly to the south of the Humber and to the north of the Thames. The modern limits are somewhat different, but the above division of the three chief dialects (excluding Kentish) into Northern, Midland, and Southern is sufficient for taking a broad general view of the language in the days before the Norman Conquest.