He reached Russia on 17 May 1917. After his return, Trotsky substantially agreed with the Bolshevik position, but did not join them right away. Russian social democrats were split into at least six groups, and the Bolsheviks were waiting for the next party Congress to determine which factions to merge with. Trotsky temporarily joined the Mezhraiontsy, a regional social democratic organization in Saint Petersburg, and became one of its leaders. At the First Congress of Soviets in June, he was elected a member of the first All-Russian Central Executive Committee ("VTsIK") from the Mezhraiontsy faction.