He killed him. They were friends, but he had him killed. Stalin murdered millions.
Stalin
See link below.
Yes, Joseph Stalin did in fact gain power in the soviet Union.He gained a lot of his power after WW2 because he was seen as a hero to the soviet union after the soviets crushed the German military in WW2.
Poland
Stalin was determined to capture West Berlin and gain concessions from the West
Joseph Stalin feared that Western Germany would gain too much power. He blockaded all roads entering the former capitol of Germany.
Stalin was willing to exploit anyone and anything to gain and remain in power. If he thought he could use something to his advantage he would do so.
In November, 1929, Stalin gained full power in the Soviet Union after expelling Nikolai Bukharin from the Politburo thereby eliminating his last remaining rival for control of the Soviet Union. Stalin had exercised partial power together with Grigory Zinoviev and Lev Kamenev after Lenin suffered his first stroke on May 25, 1922. After Lenin's death Stalin continued in partial power as he eliminated all rivals to his leadership and at last gained full power over the Soviet Union.
Stalin didn't gain anything.. But ruined his own hereafter.
It took Adolf Hitler until the early 1930's to gain political power in Germany. Joseph Stalin was part of the Bolshevik October Revolution in Russia in 1917. Stalin held important political positions , even a dictatorship in the USSR by 1930. To answer the question then, Stalin came first.
He had a group of "secret police" called the Gestapo.
He was isolated by Stalin, and basically made a public enemy. Since he had little to no support from the Soviet government, he was easily over-powered.