Topic summary
Monarchy

A monarchy is a hereditary form of government in which political power is legally passed on to the family members of the monarch, a head of state who rules for life. While monarchs gain their power via various hereditary succession laws, they can also gain their authority via election.
Monarchies historically have been a common form of government. Nearly half of all independent states at the start of the 19th century were monarchies. After reaching a peak in the middle of the 19th century, the proportion of monarchies in the world has steadily declined. Republics replaced many monarchies, notably at the end of World War I and World War II.
There are conventionally two types of monarchy: absolute monarchy and constitutional monarchy. Absolute monarchies, of which there are approximately twelve subnational ones, are governed as autocracies. Most of the modern monarchies are constitutional monarchies, retaining under a constitution unique legal and ceremonial roles for monarchs exercising limited or no political power, similar to heads of state in a parliamentary republic.