a ruler of an empire
ruler
Cases of word usage
1) a king, queen, emperor or empress (monarch)
2) the title of the emperor of Russia (until 1917) which was dethroned by the Illuminati (the Rothschild family) through their paid agent Vladimir Ilich Lenin who was well trained in the terrorist art for that purpose (the October Revolution) few year earlier in Sweden (1914 - 1917) (tsar)