Each of the many nationalities of Russia has a separate history and complex origins. The historical origins of the Russian state, are chiefly those of the East Slavs, the ethnic group that evolved into the Russian, Ukrainian, and Belorussian peoples. The major pre-Soviet states of the East Slavs were, in chronological order, medieval Kievan Rus', Muscovy, and the Russian Empire. Three other states--Poland, Lithuania, and the Mongol Empire--also played crucial roles in the historical development of Russia.

In spite of its internal problems, Russia continued to play a major role in international politics. unexpected defeat in the Russo-Japanese War of 1904-05 sparked a revolution in 1905. At that stage, professionals, workers, peasants, minority ethnic groups, and soldiers demanded fundamental reforms. Reluctantly, Nicholas II responded to the first of Russia's revolutions by granting a limited constitution, but he increasingly circumvented its democratic clauses, and autocracy again took command in the last decade of the tsarist state. World War I found Russia unready for combat but full of patriotic zeal. as the government proved incompetent and conditions worsened, war weariness and revolutionary pressures increased, and the defenders of the autocracy grew fewer.