The term 'Supreme Ruler' is used to refer to a person who holds the highest level of authority in a given area. This can include a SOVEREIGN, MONARCH, TSAR, or absolute MONARCH. A SOVEREIGN is a person who has supreme power and authority over a country or state. A MONARCH is a hereditary ruler of a country or state. A TSAR is a title used by rulers of Russia from the 15th century until the Russian Revolution in 1917. An absolute MONARCH is a ruler who has complete control over their country or state.