Russian Empire
The Russian Empire, also known as Imperial Russia or simply Russia, was an empire that existed across Eurasia and North America from 1721, following the end of the Great Northern War, until the Republic was proclaimed by the Provisional Government that took power after the February Revolution of 1917.
European Russia
Some theories say that early Eastern Slavs arrived in modern-day western Russia (also in Ukraine and Belarus) sometime during the middle of the first millennium AD. Around the middle of the first millenium the population in todays European Russia was composed of Slavic, Finno-Ugric, Turkic, Caucasian, Scandinavian, Baltic, Finnic, Khazarian, Hungarian and Norse peoples. One of the first Rus' regions was according to the Sofia First Chronicle Veliky Novgorod in 859. In late 8th and early-to-mid-9th centuries AD the Rus' Khaganate was formed in todays western Russia. The region was a place of operations for Varangians, eastern Scandinavian adventurers, merchants, and pirates. From the late 9th to the mid-13th century a large section of todays European Russia was part of Kievan Rus'. Many sources say that Ryazan, Kolomna, Moscow, Vladimir and Kiev were destroyed by the Mongol invasion. After the Mongol invasion the Muscovite Rus' arose and formed over time today's Russia. Over all this time, western Russia and the various Rus' regions had strong cultural contacts with the Byzantine Empire, while the Slavic culture was cultivated all the time. The elements of East Slavic paganism and Christianity overlapped each other and sometimes produced even double faith in Muscovite Rus'. The synthesis of Orthodox faith and Slavic paganism is still part of Russian culture.