Russia, also officially known as the Russian Federation, is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects. Russia shares borders with the following countries (from northwest to southeast): Norway, Finland, Estonia, Latvia, Lithuania and Poland (both via Kaliningrad Oblast), Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia, and North Korea. It also has maritime borders with Japan (by the Sea of Okhotsk) and the United States (by the Bering Strait).
At 17,075,400 square kilometres (6,592,800 sq mi), Russia is by far the largest country in the world, covering more than a ninth of the Earth's land area. Russia is also the ninth most populous nation in the world with 142 million people. It extends across the whole of northern Asia and 40% of Europe, spanning 9 time zones and incorporating a wide range of environments and landforms. Russia has the world's largest reserves of mineral and energy resources, and is the world's largest energy superpower. It has the world's largest forest reserves and its lakes contain approximately one-quarter of the world's fresh water.
The nation's history began with that of the East Slavs, who emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a noble Viking warrior class and their descendants, the first East Slavic state, Kievan Rus', arose in the 9th century and adopted Orthodox Christianity from the Byzantine Empire in 988, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Kievan Rus' ultimately disintegrated and the lands were divided into many small feudal states. The most powerful successor state to Kievan Rus' was Moscow, which served as the main force in the Russian reunification process and independence struggle against the Golden Horde. Moscow gradually reunified the surrounding Russian principalities and came to dominate the cultural and political legacy of Kievan Rus'. By the 18th century, the nation had greatly expanded through conquest, annexation, and exploration to become the Russian