A monarch is the sovereign head of state in a monarchy.
A monarch may exercise the highest authority and power in the state, or others may wield that power on behalf of the monarch. Typically a monarch either personally inherits the lawful right to exercise the state's sovereign rights (often referred to as the throne or the crown) or is selected by an established process from a family or cohort eligible to provide the nation's monarch.
Alternatively, an individual may become monarch by conquest, acclamation or a combination of means. A monarch usually reigns for life or until abdication.