King is the title given to a male monarch in a variety of contexts. The female equivalent is queen, which title is also given to the consort of a king, although in some cases, the title of King is given to females such as in the case of Mary, Queen of Hungary.
- In the context of prehistory, antiquity and contemporary indigenous peoples, the title may refer to tribal kingship. Germanic kingship is cognate with Indo-European traditions of tribal rulership.
- In the context of classical antiquity, king may translate in Latin as rex and in Greek as archon or basileus.
- In classical European feudalism, the title of king as the ruler of a kingdom is understood to be the highest rank in the feudal order, potentially subject, at least nominally, only to an emperor.
- In a modern context, the title may refer to the ruler of one of a number of modern monarchies. The title of king is used alongside other titles for monarchs: in the West, emperor, grand prince, prince, archduke, duke or grand duke, and in the Islamic world, malik, sultan, emir or hakim, etc.
- The city-states of the Aztec Empire had a Tlatoani, which were kings of pre-Hispanic Mesoamerica. The Huey Tlatoani was the emperor of the Aztecs.
