There is no clear definition of monarchy. Holding unlimited political power in the state is not the defining characteristic, as many constitutional monarchies such as the United Kingdom and Thailand are considered monarchies. Hereditary rule is often a common characteristic, but elective monarchies are considered monarchies (the pope, sovereign of the Vatican City State, is elected by the College of Cardinals) and some states have hereditary rulers but are considered republics (such as the stadtholder of the Dutch Republic). A 1914 edition of Bouvier's Law Dictionary states that "Monarchy is contradistinguished from republic," and gives this definition:

Currently 44 nations in the world have monarchs as heads of state, 16 of which are Commonwealth realms that recognize Elizabeth II of the United Kingdom as head of state.

Etymology

Characteristics and role

Today, the extent of a monarch's actual powers varies:

• In an absolute monarchy, the monarch rules as an autocrat, with absolute power over the state and government—for example, the right to rule by decree, promulgate laws, and impose punishments. Absolute monarchies are not necessarily authoritarian; the enlightened absolutists of the Enlightenment were monarchs who allowed various freedoms.
• In a constitutional monarchy, the monarch is largely a ceremonial figurehead subject to a constitution. Sovereignty rests formally with and is carried out in name of The Crown but politically rests with the people (electorate), as represented by the parliament or other legislature. Constitutional monarchs have little real political power, and are constituted by tradition and precedent, popular opinion, or by legal codes or statutes. They serve as symbols of continuity and the state and carry out largely ceremonial functions. Still, many constitutional monarchs retain certain privileges (inviolability, sovereign immunity, an official) and powers (to grant pardons, to appoint titles of nobility). Additionally, some monarchs retain reserve powers, such as to dismiss a prime minister, refuse to dissolve parliament, or withhold Royal Assent to legislation, effectively vetoing it.

Most states only have a single monarch at any given time, although two monarchs have ruled simultaneously in some countries (diarchy), as in the ancient Greek city-state of Sparta, and there are examples of joint sovereignty of spouses or relatives (such as William and Mary in the Kingdom of England and Scotland)A current example of constitutional diarchy is Andorra. A regent may rule when the monarch is a minor, not present or debilitated.