From the 1930s onwards, the Russian language exerted significant influence on Ukrainian, and the regime of Joseph Stalin began to actively suppress the Ukrainian language. Along with many of the other languages spoken in the Soviet Union, Ukrainian was viewed as a challenge to centralised power and the linguistic unification of the Soviet people. Terminology and wording that was similar or identical to Russian was emphasized in dictionaries, grammar books, and the official guidance issued to editors and publishers. This resulted in a generally more Russianised Ukrainian than had existed prior to the Soviet Union. After Ukraine became independent, this outcome would eventually generate disagreement regarding the question of what constitutes pure Ukrainian.