reign

The exercise of sovereign power.

“England prospered under Elizabeth I's reign.”

The period during which a monarch rules.

“The reign of Victoria was a long one.”

The territory or sphere over which a kingdom; empire; realm; dominion, etc. is ruled.

To exercise sovereign power, to rule as a monarch.

“He reigned in an autocratic manner.”

To reign over (a country)

To be the winner of the most recent iteration of a competition.

To be a dominant quality of a place or situation; to prevail, predominate, rule.

“Silence reigned.”