Reign

A reign is the period of time that a monarch (a king, queen, emperor, etc.) rules over a country. It can also be the period of time that a spiritual leader rules in a particular office. For example, the reign of a pope, dalai lama, patriarch etc. A reign can also be used for an office or championship. In many cases a reign lasts until the monarch (or leader) resigns, dies, or is removed. A monarch's reign was sometimes used to mark time officially. In Anglo-Saxon England for example, many royal documents were dated by the regnal year of the king. This lasted until about the 10th century.
Current Longest Reigning Monarchs.
Some of the longest reigning current monarchs are:
Some of the longest reigning monarchs of all time are:
Shortest Reigning Monarchs in History.
Some of the shortest reigns in history are: