Союз освобождения
Repression started in 1917 and reached its peak during the 1930s and especially during the USSR-wide Great Purge of 1937–1938. Significant executions of notable Belarusian intellectuals and politicians were carried out during the night of 29 to 30 October 1937 related to the fabricated Case of the Union of Liberation of Belarus in 1930. Thousands of ethnic Poles were killed during the Polish Operation of the NKVD (1937–38), and their families frequently deported to Kazakh Soviet Socialist Republic.