At the Sixth (Prague) All-Russia Conference of the RSDLP (1912) Semashko delivered a report on the insurance sector, consisting of a draft resolution which Lenin had edited and which the Conference adopted. In 1913 Semashko participated in the social-democratic movement in Serbia and in Bulgaria; at the beginning of World War I he was interned. Returning to Moscow in September 1917, he was elected chairman of the Bolshevik faction of the Pyatnitskaya district council. He was a delegate of the Sixth Party Congress, participated in the preparation of the armed insurrection in Moscow, and organized medical care for its participants.