The Provisional All-Russian Government was a Russian provisioinal government that ruled over Siberia from 1918 to 1920 during the Russian Civil War. The government was ruled by the Constitutional Democratic Party, the Socialist Revolutionary Party, and far-right military officers and bureaucrats, and Alexander Kolchak served as the dictator in charge of the Omsk-based government. The government collapsed due to infighting between the leftist SRs and the conservative White movement supporters under Kolchak, with the cossacks helping in the fight against the socialist SRs; many SRs would go on to defect to the Bolsheviks.