Emperor

One who rules over kings and chiefs either by fealty, alliance or conquest. Is a monarch, and usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife (empress consort), mother (empress dowager), or a woman who rules in her own right (empress regnant). Emperors are generally recognized to be of a higher honour and rank than kings.
Both emperors and kings are monarchs, but emperor and empress are considered the higher monarchical titles. Inasmuch as there is a strict definition of emperor, it is that an emperor has no relations implying the superiority of any other ruler and typically rules over more than one nation. Therefore a king might be obliged to pay tribute to another ruler,[3] or be restrained in his actions in some unequal fashion, but an emperor should in theory be completely free of such restraints. However, monarchs heading empires have not always used the title in all contexts

Type

Nobility, Hereditary