"In September 1935, civilized humanity, friends and enemies alike, learned with surprise that the Red Army would now be crowned with an officers' hierarchy, beginning with lieutenant and ending with marshal." -Leon Trotsky, "The Revolution Betrayed" - 1936

Trotsky writes in "The Revolution Betrayed", that the red army didn't have a formal officer corps until 1935. How was the Red Army commanded from 1918-1934? Was it similar to the Catalonian militias in the Spanish Civil War?

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