emperors

Sovereigns or supreme monarchs of an empire, which is a political unit that comprises a number of territories or nations and is ruled by a single supreme authority. The use of the term is often restricted to reference to such supreme authorities in only certain parts of the world, including the ancient Roman empire, the Early Christian Roman empire, and the empires of Austria-Hungary, China, Japan, Morocco, India, Asia Minor, and Germany. The rulers of conglomerate political states in other parts of the world are generally known by other titles. The term "emperors" always refers to males, while "empresses" refers to female rulers.