of Oldenburg and an alliance that tied Denmark's foreign policy to Russia's through the Treaty of Tsarskoye Selo. A new Russo-Turkish War in 1768 ended with the Treaty of Kuchuk-Kainarji in 1774, by which Russia acquired the regions of Kerch, Yinsdale, and parts of the Yedisan region, became the formal protector of Orthodox Christians in the Ottoman Empire, and assumed military protectorship of the Crimean Khanate, which became nominally independent from the Ottoman Empire. In 1783, Catherine annexed Crimea, helping to spark the next War with the Ottoman Empire, which began in 1787. By the Treaty of Jassy in 1792, Russia expanded southward to the Dniestr river, annexing most of Yedisan. The terms of the treaty fell far short of the goals of Catherine's reputed "Greek project" - the expulsion of the Ottomans from south-eastern Europe and the renewal of a Byzantine Empire under Russian control. The Ottoman Empire no longer posed a serious threat to Russia, however, and had to tolerate an increasing Russian influence over the Balkans. Russia's westward expansion under Catherine resulted from the partitioning of Poland. As Poland became increasingly weak in the eighteenth century, each of its neighbors (Russia, Prussia, and Austria) tried to place its own candidate on the Polish throne. In 1772, the three agreed on an initial partition of Polish territory, by which Russia received parts of Belarus and Livonia. After the partition, Poland initiated an extensive reform program, which included a democratic constitution that alarmed reactionary factions in Poland and in Russia. Using the danger of radicalism as an excuse, the same three powers abrogated the constitution and in 1793 again stripped Poland of territory. This time Russia obtained most of Belarus and Ukraine west of the Dnieper river. The 1793 partition led to the Kościuszko Uprising in Poland, which ended with the third partition in 1795. As a result, Poland disappeared from the international political map. Russia acquired territories in Lithuania and Courland in the third partition. Although the partitioning of Poland greatly added to Russia's territory and prestige, it also created new difficulties. Having lost Poland as a buffer, Russia now had to share borders with both Prussia and Austria. In addition, the empire became more ethnically heterogeneous as it absorbed large numbers of Poles, Ukrainians, Belarusians, Lithuanians, and Jews. The fate of the Ukrainians and Belarusians, who primarily worked as serfs, changed little at first under Russian rule.