section_path: Characteristics and role/Person of monarch
section_name: Person of monarch
paragraph_text: Person of monarch
  
  Most monarchies only have a single person acting as monarch at any given time, although two monarchs have ruled simultaneously in some countries, a situation known as diarchy. Historically this was the case in the ancient Greek city-state of Sparta. There are examples of joint sovereignty of spouses, parent and child or other relatives (such as William III and Mary II in the kingdoms of England and Scotland, Tsars Peter I and Ivan V of Russia, and Charles I and Joanna of Castile).
  
  Andorra currently is the world's only constitutional diarchy, a co-principality. Located in the Pyrenees between Spain and France, it has two co-princes: the bishop of Urgell in Spain (a prince-bishop) and the president of France (derived ex officio from the French kings, who themselves inherited the title from the counts of Foix). It is the only case in which an independent country's (co-)monarch is democratically elected by the citizens of another country.
  
  In a personal union, separate independent states share the same person as monarch, but each realm retains separate laws and government. The fifteen separate Commonwealth realms are sometimes described as being in a personal union with King Charles III as monarch; however, they can also be described as being in a shared monarchy.
  
  A regent may rule when the monarch is a minor, absent, or debilitated.
  
  A pretender is a claimant to an abolished throne or a throne already occupied by somebody else.
  
  Abdication is the act of formally giving up one's monarchical power and status.
  
  Monarchs may mark the ceremonial beginning of their reigns with a coronation or enthronement.