After the Tsar abdicated on the 2nd March 1917 the Provisional Government were placed in charge. To form this government, members of the Duma were placed in control. During the period of time between the Tsar's abdication and the Bolsheviks taking over, the provisional government made very few decisions. Before this, however, the Petrograd Soviet was set up to represent the workers and soldiers in Petrograd. They tried to undermine the Provisional government and this lead to disagreements and a coup d"etat. The abdication of the Tsar gave Lenin the chance he had been waiting for. When the Bolsheviks formed a revolution and took over Russia's government, the immediate decision, which they made, was one to discontinue the war with Germany. Each of these reasons for the Bolsheviks remaining in power are important. However, none is important enough to cause a revolution by itself. When these causes are combined together they can and did quite easily cause a revolution.
The communists were a very small group in comparison to all its opponents, but were still extremely capable of changing the course of events in the future. "The Whites" were a large army, consisting of the opposition to the Bolsheviks, under the command of Tsarist generals. "The Whites" were unorganised, uncoordinated, and were unable to help each other out. This gave the Bolsheviks an edge, as "The Whites" were unable to counter the plans made by the newly appointed "Red Army," created by Trotsky, whom quickly became second in command after joining the Bolsheviks in 1917.
The Bolsheviks were situated in a more central position, which kept the army closer together, and they could easily defend themselves in the area, which they created. This area included Moscow, the new capital of Russia, and Petrograd, still the main area of industry. "The Whites," were a mixed group of several different committees all with different opinions, and different ideas on running the army.
