The first instance of communism in the modern world was the Paris Commune after France’s collapse in the Franco-Prussian war in 1870. As soon as the communards took over the mass murder began. This was a taste of things to come in the 20th century.
Apologists for communism claim that Stalin was an aberration, just like Mao and Pol Pot were aberrations. We have a pronounced pattern here that the apologists refuse to acknowledge.
After the fall of the Soviet Union a film was made in Russia in 1991, ‘The Chekist’, that made the point in a horrific way that the mass murder in Russia did not start with Stalin but as soon as the Bolsheviks gained power. As the author contends in the article, it wasn’t Stalin but communism itself.
The Parisian Commune was in 1793; a lot of the ideas from the French Revolution found their way into Marx’s work. The idea of butchering nobles/wealthy people, attacking the Church, and eliminating class distinctions emerged in the French Revolution. The bishops on chessboards were replaced with jesters as part of the elimination of Catholicism from French society.
When communists tried to take over Spain in 1936, a lot of the same ideas took hold; they killed thousands of priests (including a dozen bishops), tried to eliminate class distinction (even trying to eliminate the formal Spanish by replacing it with the informal/familiar), and reduced the whole population to peasant subsistence.