It is very likely that, in a far distant prehistoric time, all Eastern Slavic tribes, the ancestors of the present Ukrainians, White Russians and Russians, spoke a common tongue. But soon after the beginnings of historical life in Eastern Europe we see these Slavic races divided lingually into three groups. In the 11th Century, the differences between the language spoken in Kiev or Halich on the one hand, and Vladimir on the Klasma or Sugdal on the other, were already distinct. The political unification of all the Eastern Slavic tribes in the Kiev Empire could not eradicate these differences between North and South, and they are very evident in the literary monuments of that time. The disruption of the Empire of Kiev into loosely connected principalities, the formation of the Muscovite political center, the decline of Kiev—all went to strengthen the lingual antitheses between the ancestors of the Ukrainians and those of the Russians. The Tatar oppression finally separated the Muscovite group permanently from the Ukrainian, forcing each to lead a separate historical life. The Ukraine fell under Lithuanian, then Polish rule; Muscovy gradually developed into the Russian Empire. The differences in language, which in the 14th Century were already appreciable, increased so strongly thru the independent development of each language that in the 18th Century, when Russia received the greatest part of the Ukraine beneath her dominion, the Russian and Ukrainian languages confronted one another as entirely independent languages. According to the investigations of Stotzky and Gartner, the Ukrainian language, from a philological point of view, is related to the Russian only to about the same extent that it is related to the Polish or Czechic. Of all Slavic [170]languages the nearest to the Ukrainian is the Serbo-Croatian. From this it follows that the Ukrainians must at one time have had a much closer community with the Serbo-Croations than with the Russians.