Left Socialist-Revolutionaries in the context of "Russian Constituent Assembly"

The Russian Civil War (Russian: Гражданская война в России, romanized: Grazhdanskaya voyna v Rossii) was a multi-party civil war in the former Russian Empire sparked by the 1917 overthrowing of the Russian Provisional Government in the October Revolution, as many factions vied to determine Russia's political future. It resulted in the formation of the Russian Socialist Federative Soviet Republic and later the Soviet Union in most of its territory. Its finale marked the end of the Russian Revolution, which was one of the key events of the 20th century.

The Russian monarchy ended with the abdication of Tsar Nicholas II during the February Revolution, and Russia was in a state of political flux. A tense summer culminated in the October Revolution, where the Bolsheviks overthrew the provisional government of the new Russian Republic. Bolshevik seizure of power was not universally accepted, and the country descended into a conflict which became a full-scale civil war in May–June 1918. The two largest combatants were the Red Army, fighting for the establishment of a Bolshevik-led socialist state headed by Vladimir Lenin, and the forces known as the White movement (and its White Army), led mainly by the right-leaning officers of the Russian Empire, united around the figure of Alexander Kolchak. In addition, rival militant socialists, notably the Ukrainian anarchists of the Makhnovshchina and Left Socialist-Revolutionaries, were involved in conflict against the Bolsheviks. They, as well as non-ideological green armies, opposed the Bolsheviks, the Whites and the foreign interventionists. Thirteen foreign states intervened against the Red Army, notably the Allied intervention, whose primary goal was re-establishing the Eastern Front of World War I. Three foreign states of the Central Powers also intervened, rivaling the Allied intervention with the main goal of retaining the territory they had received in the Treaty of Brest-Litovsk with Soviet Russia.

The Socialist Revolutionary Party (SR; Russian: Па́ртия социали́стов-революционе́ров, romanized: Pártiya sotsialístov-revolyutsionérov,, lit. 'Party of Socialists-Revolutionaries') was a major socialist political party in the late Russian Empire, during both phases of the Russian Revolution, and in early Soviet Russia. The party members were known as Esers (эсеры, esery, from "SRs").

The SRs were agrarian socialists and supporters of a democratic socialist Russian republic. The ideological heirs of the Narodniks, the SRs won a mass following among the Russian peasantry by endorsing the overthrow of the Tsar and the redistribution of land to the peasants. The SRs boycotted the elections to the First Duma following the Revolution of 1905 alongside the Russian Social Democratic Labour Party, but chose to run in the elections to the Second Duma and received the majority of the few seats allotted to the peasantry. Following the 1907 coup, the SRs boycotted all subsequent Dumas until the fall of the Tsar in the February Revolution of March 1917. Controversially, the party leadership endorsed the Russian Provisional Government and participated in multiple coalitions with liberal and social-democratic parties, while a radical faction within the SRs rejected the Provisional Government's authority in favor of the Congress of Soviets and began to drift towards the Bolsheviks. These divisions would ultimately result in the party splitting over the course of the fall of 1917, with the emergence of a separate Party of Left Socialist Revolutionaries. Meanwhile, Alexander Kerensky, one of the leaders of the February Revolution and the second and last head of the Provisional Government (July–November 1917) was a nominal member of the SR party but in practice acted independently of its decisions.

The Council of People's Commissars (CPC) (Russian: Совет народных комиссаров (СНК), romanized: Sovet narodnykh kommissarov (SNK)), commonly known as the Sovnarkom (Совнарком), were the highest executive authorities of the Russian Soviet Federative Socialist Republic (RSFSR), the Soviet Union (USSR), and the Soviet republics from 1917 to 1946.

The Sovnarkom of the RSFSR was founded in the Russian Republic soon after the October Revolution in 1917 and its role was formalized in the 1918 Constitution of the RSFSR to be responsible to the Congress of Soviets of the RSFSR for the "general administration of the affairs of the state". Unlike its predecessor the Russian Provisional Government which had representatives of various political parties, and except for the brief two-party cabinet with the Left Socialist-Revolutionaries from December 1917 to March 1918, the Sovnarkom was a government of a single party, the Bolsheviks. The Sovnarkom of the USSR and Congress of Soviets of the USSR founded in 1922 were modelled on the RSFSR system, and identical Sovnarkom bodies were founded in the Soviet republics and autonomous republics. The Sovnarkom evolved into the main executive of the government of the Soviet Union with its head, the Premier of the USSR, serving as head of government. The Sovnarkom issued decrees having the force of law when the Congress was not in session, and if these decrees were not approved at the Congress's next session, they were considered revoked.