tsar(redirected from Emperor of All Russias)
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(also, czar; from the latin caesar, the title used by the Roman emperors), in Russia and Bulgaria, the official title of the monarch. In Russia the title of tsar was first adopted by Ivan IV (Ivan the Terrible) in 1547. From 1721 the Russian tsars adopted the title of emperor. In Bulgaria the monarchs bore the title of tsar from the end of the 19th century to the proclamation of the People’s Republic in 1946.