Russian Autocrat is a term used to refer to the rulers of Russia from the 16th century to the early 20th century. The two most commonly used titles for these rulers were TSAR and CZAR, both of which are four letter words. TSAR was the title used by the rulers of Russia from 1547 to 1721, while CZAR was the title used from 1721 to 1917. Both titles refer to the same position of absolute power and authority in Russia.