Regent

In a monarchy, a regent  is a person appointed to govern a state  because the actual monarch is a minor, absent, incapacitated or unable to discharge their powers and duties, or the throne is vacant and a new monarch has not yet been determined. The rule of a regent or regents is called a regency. A regent or regency council may be formed ad hoc or in accordance with a constitutional rule. Regent is sometimes a formal title granted to a monarch's most trusted advisor or personal assistant. If the regent is holding the position due to their being in the line of succession, the compound term prince regent is often used; if the regent of a minor is their mother, and she is wife or widow of the king, she would be referred to as queen regent.

If the formally appointed regent is unavailable or cannot serve on a temporary basis, a regent ad interim may be appointed to fill the gap.

In a monarchy, a regent usually governs due to one of these reasons, but may also be elected to rule during the period when the royal line has died out. This was the case in the Kingdom of Finland and the Kingdom of Hungary, where the royal line was considered extinct in the aftermath of World War I. In Iceland, the regent represented the King of Denmark as sovereign of Iceland until the country became a republic in 1944. In the Polish–Lithuanian Commonwealth (1569–1795), kings were elective, which often led to a fairly long interregnum. During this period, the Roman Catholic primate (the Archbishop of Gniezno) served as the regent, and was called interrex (Latin: ruler 'between kings' as in Ancient Rome). In the small republic of San Marino, the two Captains Regent (Capitani Reggenti) are both elected for a six-month term as joint heads of state.

Famous regency periods include that of the Prince Regent, later George IV of the United Kingdom, giving rise to many terms such as Regency era and Regency architecture. Strictly, this period lasted from 1811 to 1820, when his father George III was insane, though when used as a period label it generally covers a wider period. Philippe II, Duke of Orléans was Regent of France from the death of Louis XIV in 1715 until Louis XV came of age in 1723; this is also used as a period label for many aspects of French history, as Régence in French, again tending to cover a rather wider period than the actual regency. For a period of a month and a half, the Second French Empire was a regency. The Emperor departed with his army, giving his political powers to his wife who essentially carried out all his roles and even sent him orders. He would never be able to return to France, and the empire ended as a regency two days after his defeat and imprisonment at the Battle of Sedan. The equivalent Greek term is epitropos, meaning overseer.

Liechtenstein (under Alois, Hereditary Prince of Liechtenstein) is the only country with an active regency. In 2016, Prem Tinsulanonda became the oldest regent of any nation, at the age of 96. He became the regent for Rama X of Thailand, who chose not to formally accede to the throne until the end of the mourning period for his father. Previously, this record was held by Prince Regent Luitpold of Bavaria, who was 91 at the end of his regency.

Other uses
The term “regent” may also refer to positions lower than that of a state’s ruler. The term may be used in the governance of organisations, typically as an equivalent of "director", and held by all members of a governing board rather than just the equivalent of the chief executive.

In the Society of Jesus, a regent is an individual training to be a Jesuit and who has completed his novitiate and philosophy studies but has not yet progressed to theology studies. A regent among the Jesuits is often assigned to teach in schools or some other academic institution.

Some university managers in North America are called regents, and a management board for a college or university may be titled the "Board of Regents". In New York State, all activities related to public and private education (P-12 and postsecondary) and professional licensure are administered by the Board of Regents of the University of the State of New York, the appointed members of which are titled regents.

Europe
The term "regent" is also used for members of governing bodies of institutions such as the national banks of France and Belgium.

In the Dutch Republic, the members of the ruling class, not formally hereditary but forming a de facto patrician class, were informally known collectively as regenten (the Dutch plural for regent) because they typically held positions as "regent" on the boards of town councils, as well as charitable and civic institutions. The regents group portrait, regentenstuk or regentessenstuk for female boards in Dutch, literally "regents' piece", is a group portrait of the board of trustees, called regents or regentesses, of a charitable organization or guild. This type of group portrait was popular in Dutch Golden Age painting during the 17th and 18th centuries.

Again in Belgium and France (régent in French, or in Dutch), "regent" is the official title of a teacher in a lower secondary school (junior high school), who does not require a college degree but is trained in a specialized école normale (normal school).

Southeast Asia
In the former Dutch East Indies, a regent was a native prince allowed to rule de facto colonized 'state' as a regentschap. Consequently, in the successor state of Indonesia, the term regent is used in English to mean a bupati, the head of a kabupaten (second level local government).

In Malaysia, a pemangku raja is the interim ruler of a Malay state if its king is elected to be the Yang di-Pertuan Agong for the usual five-year term, or is unable to assume their role. For example, Tengku Hassanal Ibrahim Alam Shah, became Regent of Pahang after his father, Abdullah of Pahang was elected Yang di-Pertuan Agong XVI in 2019.

In the Philippines – specifically, the University of Santo Tomas –  the Father Regent, who must be a Dominican priest and is often also a teacher, serves as the institution's spiritual head. They also form the Council of Regents that serves as the highest administrative body of the university.

Africa
In Eswatini, where succession to the throne is not immediate, the Ndlovukati (similar to a queen mother) rules as regent until the new king is determined.

In Lagos, Nigeria, the subnational Erelu Kuti rules the kingdom as regent whenever there is no Oba of Lagos. Much like in Eswatini, succession to the throne of Lagos is not immediate, and the Erelu Kuti (a high ranking functionary in her own right) is charged with serving as custodian until a successor is crowned. The use of a regency is also common in Southwestern states, predominantly Ondo and Ekiti.