Prison of peoples or prison of nations (тюрьма народов) is a phrase first used by Vladimir Lenin in 1914. He applied it to Russia, describing the national policy of that time. The idea of calling Russia a prison is based on Marquis de Custine's book La Russie en 1839.
Engels had used the phrase. It is also associated with Soviet historian Mikhail Pokrovsky's criticism of "Russia—prison of the peoples" and "Russia—international gendarmerie".
The main meaning of the phrase was the general idea of the Russian Empire as a backward authoritarian state. This definition was also sometimes used in relation to other multinational states that suppressed the desire of peoples for self-determination (Austria-Hungary, the Ottoman Empire, the USSR, Yugoslavia and others).
In "Russia as the Prison of Nations" (1930), Pokrovsky wrote that direct coercion was applied most often by the Russian Empire in areas of expansion in the Far East, Caucasus, Central Asia, and Manchuria, as well as in western parts of the empire such as Poland, and "a great many Poles ended their lives in Siberia". Pokrovsky mentioned that Ukrainian, Belarusian, and Georgian schools did not exist and that in Polish schools the speaking of Polish language was penalized by depriving meals. Pokrovsky highlighted the history of the Jews as the most outcast in tsarist rule, due to the Pale of Settlement restricting where to live. Pokrovsky cited Lenin's idea that "the dictatorship of the serf-holding landowners was not only a reflection of our country's economic backwardness, it was also one of the causes of this backwardness. As it rested on outmoded forms of economy, it did not let the economy move forward at the same time. As long as it was not overthrown, [the Russian Empire] had to remain a backward agrarian country."
Soviet historians traditionally criticized tsarist policies, which included some usage of the phrase "prison of the peoples" after Lenin. On the other hand, historians have debated how much Stalin was willing to acknowledge the existence of Lenin's and Pokrovsky's "prison of the peoples" idea.