In a historical sense, the term refers to both official and unofficial policies of Imperial Russia and the Soviet Union with respect to their national constituents and to national minorities in Russia, aimed at Russian domination.
The major areas of Russification are politics and culture. In politics, an element of Russification is assigning Russian nationals to leading administrative positions in national institutions. In culture, Russification primarily amounts to domination of the Russian language in official business and strong influence of the Russian language on national idioms. The shifts in demographics in favour of the ethnic Russian population are sometimes considered as a form of Russification as well.
Analytically, it is helpful to distinguish Russification, as a process of changing one's ethnic self-label or identity from a non-Russian ethnonym to Russian, from Russianization, the spread of the Russian language, culture, and people into non-Russian cultures and regions, distinct also from Sovietization or the imposition of institutional forms established by the Communist Party of the Soviet Union throughout the territory ruled by that party. In this sense, although Russification is usually conflated across Russification, Russianization, and Russian-led Sovietization, each can be considered a distinct process. Russianization and Sovietization, for example, did not automatically lead to Russification – change in language or self-identity of non-Russian peoples to being Russian. Thus, despite long exposure to the Russian language and culture, as well as to Sovietization, at the end of the Soviet era non-Russians were on the verge of becoming a majority of the population in the Soviet Union.
An early case of Russification took place in the 16th century in the conquered Khanate of Kazan (medieval Tatar state which occupied the territory of former Volga Bulgaria) and other Tatar areas. The main elements of this process were Christianization and implementation of the Russian language as the sole administrative language.
After the Russian defeat in the Crimean War in 1856 and the Polish rebellion of 1863, Tsar Alexander II increased Russification to reduce the threat of future rebellions. Russia was populated by many minority groups, and forcing them to accept the Russian culture was an attempt to prevent self-determinationist tendencies and separatism. In the 19th century, Russian settlers on traditional Kirghiz land drove many of the Kirghiz over the border to China.