What was the political belief that one ruler should hold all power within a country?

The political belief that one ruler should hold all power within a country is known as absolutism. This doctrine asserts that a sovereign has absolute authority and is not bound by any laws or governing bodies, often justified by the idea of divine right, which claims that the ruler's power is granted by God. Absolutism was prominent in various historical contexts, particularly in 17th and 18th century Europe, exemplified by monarchs such as Louis XIV of France.