Ukraine (Ukrainian: Україна, Ukrayina, /ukra’jina/) is a country in Eastern Europe. It borders Russia to the northeast, Belarus to the north, Poland, Slovakia and Hungary to the west, Romania and Moldova to the southwest and the Black Sea to the south. The territory of present-day Ukraine was a key centre of East Slavic culture in the Middle Ages, before being divided between a variety of powers, notably Russia, Poland, Lithuania, Austria, Romania and the Ottoman Empire. A brief period of independence following the Russian Revolution of 1917 was ended by Ukraine's absorption into the Soviet Union and the republic's present borders were only established in 1954. It became independent once more following the fall of the Soviet Union in 1991.