A regent is an acting governor. In a monarchy, a regent usually rules due to the actual monarch's absence, incapacity, or minority. In the case of Finland and Hungary, military officers served as regents in the absence of a monarch, while in Iceland, the regent represented the King of Denmark as sovereign of Iceland until the country became a republic in 1944.
In San Marino, an independent republic surrounded within Italy, the 'Captains Regent', or Capitani Reggenti, are two officials elected as joint heads of state.
In the Polish-Lithuanian Commonwealth kings were elected, which often led to relatively long interregna periods. It was the Polish primate who served as a regent, known at that time as an interrex (ruler between kings).
Occasionally, the term regent refers to positions lower than the ruler of a country; for instance, some university managers in North America are called regents. In Indonesia, the term regent is used in English to mean a bupati or local government official.
It should be noted that those who held a regency briefly, for example during surgery, are not necessarily listed, particularly if they performed no official acts; this list is also not complete.
See also: Regency