Regents

upright=1.35|thumb|16th century Swedish regent Sten Sture the Younger|Stenonis Sture and wife [[Christina Gyllenstierna who both operated in strong resistance to Danish rule during the Kalmar Union]] upright=1.35|thumb|The oath of the provisional triumvirate|triumviral regents of the [[Empire of Brazil on behalf of the 5-year-old Emperor Pedro II in 1831, at the beginning of the Regency period.]] In a monarchy, a regent () is a person appointed to execute the office of a monarch temporarily, essentially as a substitute ruler. Regencies may arise for a number of reasons, including the monarch b

The interrex (plural interreges) was an extraordinary magistrate during the Roman Kingdom and Republic. Initially, the interrex was appointed after the death of the king of Rome until the election of his successor, hence its name—a ruler "between kings" (). The position was retained during the Republic when both consuls were unable to assume their duties, especially holding elections. Interreges ruled for only five days, which often led several of them to be appointed in succession, the record being 15 interreges in 326 BC. They were exclusively chosen from among patrician senators, and during

Prince who rules in place of a monarch due to incapacity or absence