A Reichsverweser (German pronunciation: 'ʁaɪ̯çsfɛɐ̯ve:zɐ) or imperial regent represented a monarch when there was a vacancy in the throne, such as during a prolonged absence or in the period between the monarch's death and the accession of a successor. The term Verweser comes from the Old High German firwesan and means "for or in the place of a person". The plural form is the same as the singular.
In the Holy Roman Empire, Reichsverweser were used periodically, but after its dissolution in 1806, the position was occupied only for one relatively short period during the German revolutions of 1848–1849. Although there were discussions about naming a Reichsverweser at the end of World War I and during the Nazi era, none was ever appointed.
Positions similar to Reichsverweser have been used in Hungary, where they are called kormányzó, in Finland (valtionhoitaja) and in Sweden (riksföreståndare).