In Petrograd the revolution has swept away the Tsarist regime. Now a provisional government is proclaimed. The prime minister is Prince Georgy Lvov, a liberal politician active in the cooperative movement. Some of the other members of the government are more obscure, but one prominent figure is the Minister for Justice, Alexander Kerensky. Kerensky is the only socialist in the provisional government, having been elected to the Duma as a member of the Trudovik Party, a split from the Socialist Revolutionaries. Kerensky is also a member of the executive of the Petrograd Soviet, and so he straddles the parliamentary and more radical aspects of the new order.
Meanwhile, what of the Tsar? In an unlikely sequence of events his train has got stuck in the town of Pskov. There he is assailed by telegrams from Alexeev, the Russian army’s chief of staff, and other leading generals, including Brusilov. They all say that it is essential that the Tsar abdicate. Otherwise disorder will spread inexorably through Russia and it will be impossible to continue the war.
The Tsar gives in. He renounces the throne of Russia, naming his brother, Grand Duke Mikhail, as his successor (bypassing his son Alexei, whose haemophilia means that he is not expected to live long).
The Tsar abdicates (Wikipedia)