When Ddid Stalin Come to Power?
It is hard to say when Stalin 'came to power'. Lenin's leadership was based on his personal authority - the Bolsheviks were his Party - and he needed no official post to sanction that power. After Lenin's death it was impossible for any Party leader to assume the same authority. Stalin was obliged to work with a collective leadership but his growing domination of the Party apparatus enabled him to undermine his rivals by pushing forward policies which they opposed.
First, Stalin defeated Trotsky and the Left Opposition by mobilizing his supporters in the Party against them. The regional party secretaries promoted by Stalin through the Orgburo were the key to his power-base. Bukharin was his ally in this cause for the consolidation of the NEP. But after 1927 Stalin turned against Bukharin and the NEP. He mobilizing his supporters in the Party for a return to Civil War methods to fight the 'kulaks' in the 'battle for bread' and force through the Five Year Plan to industrialize the Soviet Union. It was through this struggle against Bukharin and the Right that Stalin consolidated his leadership of the Party. But even then, from 1929, he we was forced to operate in a collective leadership. It was not until the 1930s - with the cult of his personality and the growing use of terror - that Stalin broke the last restraints of the collective leadership on his power.