Russia (Россия,, ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering 17098246 km2, and encompassing one-eighth of Earth's inhabitable landmass. Russia extends across eleven time zones and shares land boundaries with fourteen countries. It is the world's ninth-most populous country and Europe's most populous country, with a population of 146 million people. The country's capital and largest city is Moscow. Saint Petersburg is Russia's cultural centre and second-largest city. Other major urban areas include Novosibirsk, Yekaterinburg, Nizhny Novgorod, and Kazan.
The East Slavs emerged as a recognisable group in Europe between the 3rd and 8th centuries CE. The first East Slavic state, Kievan Rus', arose in the 9th century, and in 988, it adopted Orthodox Christianity from the Byzantine Empire. Rus' ultimately disintegrated, with the Grand Duchy of Moscow growing to become the Tsardom of Russia. By the early 18th century, Russia had vastly expanded through conquest, annexation, and the efforts of Russian explorers, developing into the Russian Empire, which remains the third-largest empire in history. However, with the Russian Revolution in 1917, Russia's monarchic rule was abolished and replaced by the Russian SFSR—the world's first constitutionally socialist state. Following the Russian Civil War, the Russian SFSR established the Soviet Union (with three other Soviet republics), within which it was the largest and principal constituent. At the expense of millions of lives, the Soviet Union underwent rapid industrialization in the 1930s, and later played a decisive role for the Allies of World War II by leading large-scale efforts on the Eastern Front. With the onset of the Cold War, it competed with the United States for global ideological influence; the Soviet era of the 20th century saw some of the most significant Russian technological achievements, including the first human-made satellite and the first human expedition into outer space.
