Ivan IV, also known as Ivan the Terrible, was a notorious Tsar of Russia who ruled from 1547 to 1584. Some synonyms for Ivan IV could include Ivan the Dread, Ivan the Formidable, Ivan the Fearsome, or Ivan the Awesome. While these titles reflect the powerful and often brutal reputation of Ivan IV, it is important to remember that his reign also saw important developments in Russian history, such as the creation of the tsarist autocracy and expansion of the Russian Empire. Nonetheless, Ivan IV's legacy remains complex and controversial, and his reputation as both a visionary leader and a cruel despot continues to be debated by historians.