Reign

A reign is the period of a person's or dynasty's occupation of the office of monarch of a nation (e.g., Saudi Arabia, Belgium, Andorra), of a people (e.g., the Franks, the Zulus) or of a spiritual community (e.g., Catholicism, Tibetan Buddhism, Nizari Ismailism). In most hereditary monarchies and some elective monarchies (e.g., Holy Roman Empire) there have been no limits on the duration of a sovereign's reign or incumbency, nor is there a term of office. Thus, a reign usually lasts until the monarch dies, unless the monarchy itself is abolished or the monarch abdicates or is deposed.

In elective monarchies, there may be a fixed period of time for the duration of the monarch's tenure in office (e.g., Malaysia).

The term of a reign can be indicated with the abbreviation "r." (for Latin '''') after a sovereign's name, such as the following: :George VI, King of Great Britain, Ireland and the British Dominions, Emperor of India (r. 1936–1952) Provided by Wikipedia