The leader of the Bolsheviks was Lenin. The number two guy was Trotsky. Stalin, in 1917, was just one of many high officials when the Bolsheviks seized power. When Lenin died in 1924, Stalin took over, but he did not consolidate his power until 1928. There was a titanic struggle betweeen him and Trotsky. Trotsky lost, fled the country, and Stalin later had him murdered in Mexico.
The genocide of Russian Christians began in 1918 and increased steadily up through Stalin's era. By the time WWII broke out, between 20-30 million people had been mass executed, tortured and executed in the CheKa basements, worked to death in the labor camps, starved to death in intentional famines. Stalin's purges eliminated the "Old Bolsheviks". Stalin was preparing an invasion of all Europe when Hitler struck. During WWII, the Bolshevik genocide back in Russia actually intensified. (we allied with those monsters, to give you an idea of what Jewish control of the media does) The Bolshevik genocide of Chrisrtians continued long after Hitler was defeated up into the 1980s. the 66 million figure is Solzhenitsyn's number. I trust him more than Wikipedia, that's for sure.
Notice that the Nazi's genocided more Europeans than Jews in the chart below
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