In May 1918, soldiers of the Czechoslovak Legion revolted against the Bolsheviks in Chelyabinsk. They were angry because the Bolsheviks had ordered the Czechoslovak troops to disarm, breaking former agreements. The Legion was trying to evacuate to the Western Front to continue the fight against the Central powers, but after the Treaty of Brest-Litovsk in March, the Bolsheviks no longer supported this move. The revolt quickly spread across Siberia, because the Czechoslovaks used the Trans-Siberian Railway to move their troops east quickly and because they were supported by local uprisings instigated by Russian army officers. When the uprising reached Yekaterinburg, the former Tsar and his family who were being held there by the Bolsheviks were executed to prevent their capture by the Whites. By the end of August, Vladivostok was in Czechoslovak hands. In the power vacuum left by the departure of the Bolsheviks multiple White Movement governments were established, most importantly KOMUCH at Samara and the Provisional Siberian Government. KOMUCH quickly ordered a general mobilisation, but its troops were small and badly trained. The Czechoslovaks allied with KOMUCH and advanced to the west, taking Kazan, where they captured the tsar's gold reserves which had been moved east for safekeeping.
In Petrograd, Lenin had called upon factory workers to be dispatched to the Eastern Front.