Great World War I started by the assassination of Archduke Franz Ferdinand by Gavrillo Princip, member of the Bosnian Youth movement, in Sarajevo. * 1917 October Revolution: the communists seize power in Russia. The USSR is formed. * 1924 Adolf Hitler, leader of the NSDAP disappears. The party falls apart due to infighting within the KPD, preventing the rise of Nazi Germany.