Regnant

A monarchy is a form of government in which a group, usually a family called the dynasty, embodies the country's national identity and one of its members, called the monarch, exercises a role of sovereignty. The actual power of the monarch may vary from purely symbolic (crowned republic), to partial and restricted (constitutional monarchy), to completely autocratic (absolute monarchy). Traditionally and in most cases, the monarch's post is inherited and lasts until death or abdication, but there are also elective monarchies where the monarch is elected. Each of these has variations: in some elected monarchies only those of certain pedigrees are, whereas many hereditary monarchies impose requirements regarding the religion, age, gender, mental capacity, etc. Occasionally this might create a situation of rival claimants whose legitimacy is subject to effective election. Finally, there have been cases where the term of a monarch's reign is either fixed in years or continues until certain goals are achieved: an invasion being repulsed, for instance. Thus there are widely divergent structures and traditions defining monarchy.

Monarchy was the most common form of government until the 19th century, but it is no longer prevalent. Where it exists, it is now usually a constitutional monarchy, in which the monarch retains a unique legal and ceremonial role, but exercises limited or no official political power: under the written or unwritten constitution, others have governing authority. Currently, 47 sovereign nations in the world have monarchs acting as heads of state, 19 of which are Commonwealth realms that recognise Queen Elizabeth II as their head of state. All European monarchies are constitutional ones, with the exception of the Vatican City which is an elective monarchy, but sovereigns in the smaller states exercise greater political influence than in the larger. The monarchs of Cambodia, Japan, and Malaysia "reign, but do not rule" although there is considerable variation in the degree of authority they wield. Although they reign under constitutions, the monarchs of Brunei, Morocco, Oman, Qatar, Saudi Arabia and Swaziland appear to continue to exercise more political influence than any other single source of authority in their nations, either by constitutional mandate or by tradition.

...
Wikipedia