Explanation: After the death of Vladimir Lenin, the chief figure of the early Soviet Union, Trotsky, his right-hand man, would not attend Lenin’s funeral, damaging Trotsky’s political standing.

… Trotsky didn’t attend because Stalin, one of his political rivals, gave Trotsky the wrong date for the funeral.

Stalin would go on to claim the position of political preeminence in the post-Lenin Soviet Union, and exile and (eventually) assassinate Trotsky. And also embark on a fuckton of massacres, genocides, and general repression of the proletariat.