Stalin utilized many different methods to exert control over the Soviet Union. Stalin was quick to manipulate circumstances to his advantage. In 1934, he used the assassination of a high-ranking communist party official to purge the party of his enemies. He orchestrated show trials and imprisoned his political enemies in Gulags, which were Soviet prisons in Siberia for political dissenters. There will also mass executions of supposed “enemies of the state” most of who were Trotsky supporters or immigrants from other countries. Then, he distanced himself from the violence by blaming another enemy and executing him for the whole ordeal.
Stalin kept tabs on both enemies and supposed allies with the NKVD, a branch of the Soviet Secret Police who gathered evidence against Stalin's enemies and then helped orchestrate mass executions.
To keep control of the common people, Stalin created a Cult of Personality around himself and Lenin. Cities were renamed after famous communist leaders, awards were named after him, he accepted ostentatious titles like, “Father of the Nation, and he even rewrote the history of the Soviet Union to give himself a more central role in the formation of the government.
Stalin assassinated his poltical opponents.
"In 1940, Trotsky was murdered with an ice-pick in Mexico on Stalin's orders by Ramon Mercader, a Spanish-born agent for the Soviet secret police."