
At the expense of millions of lives, the Soviet Union underwent rapid industrialisation 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. 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.

However, with the Russian Revolution in 1917, Russia's monarchic rule was abolished and eventually replaced by the Russian SFSR-the world's first constitutionally socialist state. 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. Rus' ultimately disintegrated, with the Grand Duchy of Moscow growing to become the Tsardom of Russia. The first East Slavic state, Kievan Rus', arose in the 9th century, and in 988, it adopted Orthodox Christianity from the Byzantine Empire. The East Slavs emerged as a recognisable group in Europe between the 3rd and 8th centuries CE. Other major urban areas in the country include Novosibirsk, Yekaterinburg, Nizhny Novgorod, Chelyabinsk, Krasnoyarsk, and Kazan. Saint Petersburg is Russia's cultural centre and second-largest city. The country's capital and largest city is Moscow.

It is the world's ninth-most populous country and Europe's most populous country. Russia extends across eleven time zones and shares land boundaries with fourteen countries. It is the largest country in the world by area, its vast landmass stretching over the easternmost part of Europe and the northernmost part of Asia.

Russia ( Russian: Россия, romanized: Rossiya, ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia.
