reign
n. countablen. the period of time when a king, queen, or leader is in power. It can also describe a time when one person or thing is the most important or successful.
n. the period during which a sovereign occupies a throne or exercises supreme authority. By extension, it refers to a period of dominance or influence by a specific person or entity in a particular field.
The queen's reign lasted for over sixty years.
The team's long reign as league champions finally ended when their star player retired last season.
Historians often debate whether the emperor's reign was defined more by his ambitious architectural projects or by the administrative reforms that stabilised the borders for a century.
From Middle English regnen, from Old French reignier, from the Latin verb rēgnō, and the noun rēgnum. Doublet of regnum. Displaced native Old English rīċe (“a reign”) and ricsian (“to reign”).
Often used with the preposition 'of' to specify the ruler or 'over' to specify the territory.