There were eight female monarchs. In other words, there were six female emperors including two who reigned twice.
- Empress Jingū r. 206–269 —legendary/mythical; removed from the list of emperors in the 19th century[source?]
- Empress Suiko (554–628), r. 593–628—first ruling empress
- Empress Kōgyoku (594–661), r. 642–645—formerly Princess Takara (Empress Consort of Jomei)
- Empress Saimei (594–661), r. 655–661 (same person as Empress Kōgyoku)
- Empress Jitō (645–702), r. 690–697
- Empress Gemmei (661–721), r. 707–715
- Empress Genshō (680–748), r. 715–724—formerly Princess Hidaka
- Empress Kōken (718–770), r. 749–758
- Empress Shōtoku (718–770), r. 764–770 (same person as Empress Kōken)
- Empress Meishō (1624–1696), r. 1629–1643
- Empress Go-Sakuramachi (1740–1813), r. 1762–1771—most recent ruling empress
The wife of an Japanese emperor is called empress in English, but her title in Japanese is a little different.
Kōgō is the title of a non-reigning empress consort. The title, still in use, is generally conferred on an emperor's wife who had given birth to the heir to the throne. The title was first awarded posthumously in 806 to the late mother of Emperor Heizei.
The numbers of kōgō varied, but there was only one Chūgū at a time.
The title kōtaigō was given to the wife of an ex-emperor; and the title tai-kōtaigō came to be used by a dowager empress.
- Nussbaum, "Michiko" at p. 627. Compare Imperial Household Agency (Kunaichō), Ceremony of Accession (Sokui-no-Rei); retrieved 2013-3-5.
- "Life in the Cloudy Imperial Fishbowl," Japan Times. March 27, 2007.
- Nussbaum, Louis-Frédéric. (2005). "Kōgō" in Japan Encyclopedia, p. 543.
- Ponsonby-Fane, Richard. (1959). The Imperial Family, p. 318.
- Nussbaum, "Chūgū" at p. 127.
- Ponsonby-Fane, pp. 300–302.