Regent

A regent is a position of government in a country where there is a monarchy (like a king or queen). As an "acting monarch" the regent does the job of a monarch where the real monarch is either too young, sick or cannot do what they are meant to for some other reason.

A regent may also be voted in if there are no heirs in line to the throne, for example, if the monarch that is ruling at the time dies with no living relatives.