When in Russia broke the February Revolution, Lenin (Vladimir Il'ič Ul'janov, 1870 - 1924) was still in exile in Switzerland. Aware that his return could trigger an even sharper opposition to the war, the Russian provisional government - agree with the Entente powers - denied him the passage to return to Russia. With twenty-seven other political exiles, he was thus forced to travel by train through Germany, already knowing that the fact would be the subject of speculation of his political opponents, who have accused him of being a German agent. In turn, the German Government, knowing that the revolution would weaken the Russian army, allowed Lenin to arrive in Petrograd through German territory. However, for internal reasons, and fearing the propaganda of the "defeatist", the German authorities decided to block three of the four entrances of the railway car to prevent any contact with the population. Thus was born the legend of the "sealed train". Arriving in Petrograd on April 3, he traced the April Theses, a ten-point plan published on April 20, which would become the political program of the Bolsheviks, and which provided, in the first place, the assignment of all power to the Soviets, the immediate withdrawal from the war and the opposition to the provisional government: it was the beginning of the October revolution.