<human>:  When did the Great Terror begin in Stalinist Russia?
<bot>: The Great Terror began in 1937, but lasted until 1953. The Great Terror was a series of political purges in the Soviet Union during the 1930s and early 1940s. It was a period of intense repression of the Soviet Union's political and social opposition, which resulted in the deaths of millions of people. The period is considered to be one of the darkest periods in the history of the Soviet Union and the Russian Federation.