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 rexit) 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)
Notable reigns have included the following.
A reign can be ended in three ways:
- Emperor Ferdinand I of Austria, King of Hungary and Bohemia, King of Lombardy-Venetia (r. 1835-1848) was abdicated due to his disabilities (feeble-mindedness and epilepsy). His successor, Emperor Franz Josef (r. 1848–1916) reigned for 68 years.
- King Edward VIII reigned from January to December 1936 before he abdicated the throne. After his abdication he became known as the Duke of Windsor. No other monarch of the Kingdom of Great Britain (1707-1800), the United Kingdom of Great Britain and Ireland, the United Kingdom of Great Britain and Northern Ireland, or any Dominion or Commonwealth realm has ever abdicated, though forced abdications did occur on rare occasions in the Kingdom of England and the Kingdom of Scotland prior to their merger in 1707.
- Queen Wilhelmina of the Netherlands reigned from 1890 to 1948, before abdicating in favor of her daughter, Queen Juliana who then reigned until 1980 when she abdicated in favor of her daughter, Queen Beatrix of the Netherlands. Beatrix followed suit and abdicated in 2013 in favor of her son and heir apparent, King Willem-Alexander.