populists, the factory organisation favoured by the People's Rights Party and the terrorist tactics embraced by the remnants of 'The People's Will' and some of the revolutionary groups of Moscow and Petrograd. In September 1904, together with Viktor Chernov and Yevno Azef, he negotiated with Plekhanov, Ulyanov and other social democrats in order to convince them to take part in the common cause. During the 1905 Russian Revolution, Natanson moved in Finland. At the first congress of the Socialist-Revolutionary Party in early 1906, he was elected a member of the Party Central Committee. After the revolution was put down, he returned to exile in Switzerland. Natanson still held a reserved position in relation to the party’s terrorist tactics. In 1906, he was an opponent of the assassination of George Gapon, the decision on which was made without his consent. At his insistence, the party refused to take responsibility for this murder. In 1907, he opposed the plan for the murder of Nicholas II, developed by Azef and Grigory Gershuni. However, in 1908, when Vladimir Burtsev began a campaign to expose Azef as an agent provocateur, Nathanson defended Azef. Until the very end, he refused to believe in Azef’s cooperation with the secret police. In his memoirs, Burtsev wrote that Natanson was the most evil of his opponents. Years of exile When the First World War broke out in 1914, the SRs, like most other European socialist parties, split into those who supported a war of 'national defence' ('Defencists') and those who opposed the war ('Internationalists'). Natanson sided with the 'Internationalists' and attended the international socialist peace conferences such as the Zimmerwald Conference and one at Kienthal in Switzerland, signing the conference's manifestoes on behalf of the SR Internationalists. Founder of Left SRs After the February Revolution broke out, Natanson returned to Russia through German territory "in a sealed wagon", as did Lenin. He became one of the most prominent leaders of the left wing of the SRs, which became increasingly disenchanted with the Provisional Government and with Alexander Kerensky and sharply criticised the defensive position of the SR central committee. Natanson advocated the "deepening" of the revolution, the transfer of all land to peasants and of power to the soviets. Natanson and the "Left SRs" supported the October Revolution, which caused a split in the Socialist Revolutionary Party. In November 1917, he initiated the creation of the party of Left