differences of these languages one from another had already crystallized by the ninth century, that is to say, at the time when the migrations of the Slavonic tribes were complete, before the formation amongst them of separate political states, and before the time to which even the earliest extant fragments of these languages belong. It is, however, probable that many of the characteristics peculiar to each of the Slavonic languages as we know them to-day had already developed in the ninth century, because considerable expansion westwards, southwards, and eastwards of the Slavonic tribes had already taken place, and consequently distinctions of nationality had time to appear and had acquired space to develop.
To the western group, the first to be considered, belong those of the Slavonic languages spoken by the tribes who in the middle of the ninth century were settled north of the Danube and west of the so-called Baltic nationalities; the boundary between the western and eastern group (not accurately to be determined even to-day) roughly corresponds to the watershed between the Vistula and the Dnieper. That between the western and southern group is approximately indicated by the Danube. In the course of their migration westward Slavonic tribes belonging to this western division had penetrated as far as the Elbe and even beyond, and at the moment when our authentic knowledge of their history begins they were in possession of the whole of the country from the mouth of the Vistula to that of the Eider in Holstein, bounded on the north by the Baltic, on the west by the Elbe, the Saal, and the Bohemian Forest (Böhmer Wald).
From among the many names of these Western Slavonic tribes that have been preserved, those have acquired greater prominence which correspond to the three important Western Slavonic languages of to-day. These are Lusatian-Wendish, Polish, and Čech, sometimes misnamed Bohemian.
The first of these three, taken geographically, is Lusatian-Lusatian-
