tsarina
The term "tsarina" (sometimes spelled "czarina") refers to the empress or queen consort of a Tsar, the emperor of Russia or some other Slavic countries. The masculine form of the title is Tsar. The title of Tsar originated from the Roman title Caesar and became synonymous with supreme ruler in Russia. Therefore, a tsarina was the wife of the supreme ruler. In cases where a woman herself held supreme power, she would be known as a tsarina in her own right, or an empress.
The most famous examples of women who held the title of tsarina are Catherine I and Catherine