belonged to the Ruthenian princedoms of Halych-Volhynia, Polotsk, Lutsk, Terebovlia, Turov-Pinsk etc. The majority of these principalities have been ruined during the Tatar–Mongol invasion in the middle of the 13th century. Some territories in the Dnieper region and Black Sea Coast for long years lost Ruthenian settled population and became the so-called Wild Steppe (i.e., territory of the Pereyaslavl). After the Tatar–Mongol invasion these territories become an object of expansion of the Polish kingdom and the Lithuanian princedom. For example, in the first half of 14th century Kiev, the Dniepr region, also the region between the rivers Pripyat and West Dvina were captured by Lithuania, and in 1352 the Halych-Volhynia princedom was divided by Poland and Lithuania. In 1569, according to the Lublin Union, the majority of the Ruthenian territories possessed by Lithuania, passed to the Polish crown. The serfdom and Catholicism extended in these territories. The local aristocracy was incorporated into the Polish aristocracy. Cultural, language and religious break between the supreme and lowest layers of a society arose. The combination of social, language, religious and cultural oppressions had led to destructive popular uprisings of the middle of 17th century, which the Polish–Lithuanian state could not recover from. In many territories incorporated into the Russian Empire in 1772–1795 after the partitions, the domination of the Polish aristocracy was kept, in the territories incorporated into the Austro-Hungarian Empire, the domination of the Polish aristocracy has been added with active planting of German language and culture. During the First World War Austro-Hungarian authorities undertook reprisals against Russia-oriented people of the Eastern Galicia and the Polish left-nationalist movement led by Piłsudski got the support of the Central Powers for struggle against Russia. In the consequence of the revolution in Russia and the fall of Hohenzollern and Habsburg empires in the end of World War I Poland regained independence. The Polish leaders decided to retrieve as many of the territories that were parts of the Polish–Lithuanian state in 1772 as possible. The situation In the aftermath of World War I, the map of Central and Eastern Europe had drastically changed. The Treaty of Brest-Litovsk (March 3, 1918), by which Russia had lost to Imperial Germany all the European lands that Russia had seized in the previous two centuries, was rejected by the Bolshevik government in November 1918, following armistice, the surrender of Germany and her allies, and the end of World War I.