She reigns suo jure (in her own right) over a realm known as a kingdom; as opposed to a queen consort, who is married to a reigning king; or a queen regent, who is the guardian of a child monarch and rules pro tempore in the child's stead or instead of her husband who is absent from the realm, be it de jure in sharing power or de facto in ruling alone.
In Ancient Africa, Ancient Persia, Asian and Pacific cultures, and in some European countries, female monarchs have been given the title king or its equivalent, such as pharaoh, when gender is irrelevant to the office, or else have used the masculine form of the word in languages that have grammatical gender as a way to classify nouns.
Among the Davidic Monarchs of the Kingdom of Judah, there is mentioned a single queen regnant, Athaliah, though the Hebrew Bible regards her negatively as a usurper.
Methods of succession to kingdoms, tribal chiefships, and such include nomination (the reigning monarch or a council names an heir), primogeniture (in which the children of a monarch or chief have preference in order of birth from eldest to youngest), and ultimogeniture (in which the children have preference in the reverse order of birth from youngest to eldest).
In the late 20th and early 21st centuries, Sweden, Norway, Belgium, the Netherlands, Denmark, Luxembourg[3] and the United Kingdom[4] amended their laws of succession to absolute primogeniture (in which the children of a monarch or chief have preference in order of birth from eldest to youngest regardless of gender).
[6] Following Elizabeth's death, Margrethe II of Denmark became the only remaining female monarch of a sovereign state in the world, until her abdication on 14 January 2024.
[a] In China the term nǚhuángdì (女皇帝, "female emperor"), abbreviated as nǚhuáng (女皇), has been used for three empresses regnant to assume the title of huángdì: Daughter of Xiaoming, Chen Shuozhen and Wu Zetian, because the title huánghòu (皇后, "emperor's consort") means only an empress consort.
In Korea, the term yeowang (Hangul: 여왕, Hanja: 女王, "female king") was developed to refer to three queens regnant of Silla: Seondeok, Jindeok and Jinseong, because the title wangbi (Hangul: 왕비, Hanja: 王妃, "king's consort") means only a queen consort.
[10][11] The term yeoje (Hangul: 여제, Hanja: 女帝, "female emperor") was also used for Yi Hae-won, the titular empress regnant of Korean Empire because the title hwanghu (Hangul: 황후, Hanja: 皇后, "emperor's consort") means only an empress consort.
Prime Minister Junichirō Koizumi pledged to present parliament with a bill to allow women to ascend the Imperial Throne, but he withdrew this after the birth of Prince Hisahito (Naruhito's nephew) in 2006.