This happened in April of 1917. He had been living in exile in Switzerland when the March Revolution broke out. The Germans provided him with a sealed train to take him across their territory in the hope that he would cause enough trouble in Russia to get Russia to drop out of the war. Immediately upon arrival, he called for "Peace, Land, Bread", No cooperation with the Provisional Government, and "All Power to the Soviets". Previously, the Bolsheviks in the Soviet had been working with the Provisional government, so this was a change of policy.