Reign (Noun)

A period during which something or somebody is dominant or powerful; "he was helpless under the reign of his egotism".

Nouns denoting time and temporal relations.

The king's reign was marked by a series of brutal wars and oppressive policies.
Her reign as the CEO of the company was cut short due to allegations of corruption.
The reign of the dinosaurs lasted for over 150 million years, until their sudden extinction.
The musician's reign as the most popular artist in the country was finally coming to an end.
The team's reign as league champions was expected to continue for several more years.

The period during which a monarch is sovereign; "during the reign of Henry VIII".

Nouns denoting time and temporal relations.

The construction of the grand cathedral was completed during the reign of Queen Elizabeth I.
King Louis XIV's reign is often referred to as the Golden Age of France.
The economic downturn occurred during the reign of President John F. Kennedy.
The dynasty's power began to wane towards the end of the emperor's reign.
Historians have debated the significance of the policies implemented during the reign of King George III.

Royal authority; the dominion of a monarch.

Nouns denoting natural processes.