The Central Committee of the Left SRs ultimately ordered the assassination of Wilhelm von Mirbach in an attempt to cause Russia to re-enter World War I and launched an ill-fated uprising against the Bolsheviks shortly after.

The internal faction was highlighted in the First All-Russian Congress of Soviets of Workers' and Soldiers' Deputies in mid-May 1917 for its position close to that of the Bolsheviks, while the bulk of the party aligned with the Mensheviks.

[4] Except for Mark Natanson,[5] at the head of the faction was a series of young leaders, from exile (Boris Kamkov), from Siberia (Maria Spiridonova[6]) or agitation activities among the population (Prosh Proshian).

[10] During the congresses of the regional, national and provincial soviets held between August and November, it was the effective division of the Right SRs and the strength of those on the left that often allowed the approval of leftist motions.

[27] They refused to join the Sovnarkom, although they did accept twenty-nine seats (compared to the sixty-seven of the Bolsheviks and twenty of other minor groups) in the new All-Russian Central Executive Committee that emerged from the congress.

[34] During the rebellion, the Left SRs had maintained a similar position to that of the Bolsheviks, participating in agitation in favor of the dissolution of the Russian Provisional Government, the transfer of power to the soviets and chairing the Petrograd Military Revolutionary Committee.

[citation needed] Subsequently, the SR Central Committee began to dissolve local groups that they considered to be rebels,[30] beginning with the largest in the country, that of the capital, with around forty-five thousand members.

[31] Although the true extent of the split unleashed by the PSR Central Committee is unknown,[39] it is considered to have been remarkable and deprived the Socialist Revolutionaries of most of its radical elements and most of its support among the soldiers, while the intelligentsia remained mainly in the old party and the peasantry was divided between the two formations.

[47][48][49][50] However, the refusal of the Right SRs to participate and the pressure of its most extreme supporters made the party abandon this cause[50] and agree to negotiate with the Bolsheviks its entry into the revolutionary government, even if the rest of the socialist formations did not enter it.

[52] The idea of a broad socialist coalition government had received widespread support, including among the Bolsheviks, during the Soviet Congress, in which a motion to this effect by Julius Martov had initially been unanimously approved.

[41] This had been called by mutual agreement between the Bolsheviks and left-wing socialist revolutionaries, to eliminate the Right SR leadership that still dominated the executive committee of the peasant soviets and that rejected the October Revolution.

[30] During their conversations with the Bolsheviks that ended their entry into the Government, they demanded control of the Ministry of Justice because of their opposition to terror,[59] with the intention of stopping it, and they obtained this portfolio for Isaac Steinberg.

[51][64] Three days later, the Agriculture Ministry [49] passed into the hands of the left-wing socialist revolutionary Andrei Kolegayev and Left SR deputy commissioners were appointed in other government posts.

[71][72][73] Partly their low presence on the Socialist Revolutionary lists was due to the youth and lack of experience of many of its future members, which made them seem unsuitable candidates to represent the party.

[74] The Left SRs wanted to approve extensive political and social changes in the assembly, but had no intention of submitting to parliamentary procedures to achieve its revolutionary objectives, as was the case with the Bolsheviks.

But the leftists became increasingly dependent on Lenin's party and lost their political power base by approving the union of the soviets, as the peasant section was now subordinated to that of the workers and soldiers, controlled by the Bolsheviks.

[94] The socialist revolutionary Peter Aleksandrovich, lieutenant of Felix Dzerzhinski, obtained great power in the Cheka, imposing unanimous votes in the troikas' that judged the most serious cases of counterrevolutionary activity, which in practice gave the veto over the death sentences.

[1][95] At a meeting of the All-Russian Central Executive Committee on February 23, the Left Socialist Revolutionaries criticized the Bolsheviks for their repressions on trade union freedoms and voted against the signing of the treaty.

[1] The signing of the peace treaty, rejected by the Left SRs, the campaign to divide the peasantry and loot [113] from the countryside to supply the cities,[108] [note 1] the final takeover of the soviets by the Bolsheviks with the expulsion of Social Revolutionaries and Mensheviks (14 June[114][111]),[108] economic and political centralization,[59] the creation of a professional Army with tsarist officers,[115][116] the restoration of the death penalty (May 21) [108] and the sharpening of terror made the Left SRs an implacable enemy of the Bolsheviks.

[122] Seeking to secure a majority in the congress, on June 14 Lenin ordered the expulsion of the Mensheviks and the Right SRs from the All-Russian Central Executive Committee (VTsIK) to undermine their chances of getting delegates.

[128] Spiridonova raised the provocation of the imperialist invasion to cause uprisings like those taking place in Ukraine, a position that was rejected by other delegates, who were not convinced of the disposition of the population to rise up against the occupiers.

[137] Felix Dzerzhinski himself, sent to the Moscow headquarters of the Cheka in search of the assassins, was arrested by the Left SR central committee, gathered there, when he believed that the socialist revolutionaries were not involved.

[137][108] Fearful of the German imperialist reaction, Lenin declared, on the contrary, that the murder was part of an attempt by the Left SRs to destroy the government of the soviets and ordered the crushing of the revolt.

[139] Attempts to take the centers into the hands of the Left SRs in Moscow, however, could not begin firmly on that night due to a lack of troops, and finally began at noon the following day, with the use of artillery against the Cheka headquarters.

[145] In Petrograd, after short but hard fighting,[126] the local headquarters of the Socialist Revolutionaries were seized; Those arrested were gradually released, after no connection to the events in Moscow was found, despite the initial fear of the Bolsheviks.

[144] During the month of July, the Bolsheviks forcibly dissolved the soviets in which the Left SRs had a majority, while expelling the Socialist Revolutionaries where they were a minority and did not agree to reject the actions of their central committee.

[155] Although the practical consequences of this decree were very few, the tolerance of the committees by the Left SR congress, generally rejected in the countryside, ended up ruining the strength of the party in rural Russia.

[157] The most radical current of the party, around Kamkov and Irina Kakhovskaya, formed a clandestine terrorist group that carried out the murder of the German Commander in Ukraine, Hermann von Eichhorn and other minor actions, disrupted by the authorities.

[160] A number of Left Socialist Revolutionaries, such as Alexander Antonov, played a significant political and military role during the Russian Civil War, joining the green rebels and fighting both the Bolsheviks and the White Guards.

[citation needed] The leaders who survived this stage, either in prison or in internal exile, fell victims to the Great Purge in the late 1930s (Algasov, Kamkov and Karelin were shot in 1938, while Spiridonova was executed in 1941).