In development of the Third Rome ideas, the Grand Duke Ivan IV (the "Awesome" or "the Terrible") was officially crowned the first Tsar ("Caesar") of Russia in 1547. The Tsar promulgated a new code of laws (Sudebnik of 1550), established the first Russian feudal representative body (Zemsky Sobor) and introduced local self-management into the rural regions. During his long reign, Ivan IV nearly doubled the already large Russian territory by annexing the three Tatar khanates (parts of disintegrated Golden Horde): Kazan and Astrakhan along the Volga River, and Sibirean Khanate in South Western Siberia. Thus by the end of the 16th century Russia was transformed into a multiethnic, multiconfessional and transcontinental state.