Belarus, officially the Republic of Belarus, and historically Byelorussia, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Covering an area of 207,600 square kilometres and with a population of 9.3 million, Belarus is the thirteenth-largest and the twentieth-most populous country in Europe. The country is administratively divided into seven regions. Minsk is the capital and largest city.
Until the 20th century, different states at various times controlled the lands of modern-day Belarus, including Kievan Rus', the Principality of Polotsk, the Grand Duchy of Lithuania, the Polish–Lithuanian Commonwealth, and the Russian Empire. In the aftermath of the Russian Revolution in 1917, different states arose competing for legitimacy amidst the Civil War, ultimately ending in the rise of the Byelorussian SSR, which became a founding constituent republic of the Soviet Union in 1922. After the Polish-Soviet War, Belarus lost almost half of its territory to Poland.