- For the Zen Buddhist monk, see Keian Genju (1427–1508).
Keian (慶安) was a Japanese era name (年号 nengō, "year name") after Shōhō and before Jōō. This period spanned the years from February 1648 through September 1652. The reigning emperor was Go-Kōmyō-tennō (後光明天皇).
Change of era
- 1648 Keian gannen (慶安元年): The new era name was created in response to criticism that Shōhō was too closely related to Shōbō (焼亡, meaning "death by burning"). The previous era ended and a new one commenced in Shōhō 5, on the 5th day of the 2nd month.
The new era name was drawn from the Chinese classic, The I Ching: "At the end happiness, joy of quiet righteousness, answer the world unlimited" (乃終有慶、安貞之吉、応地無疆):
Events of the Keian era
- April 1, 1649 (Keian 2, 20th day of the 2nd month): There was a major earthquake in Edo.
- 1651 (Keian 4): Keian Uprising. Plans by well-organized rōnin to attack several Tokugawa strongholds simultaneously were timely discovered. The attempt plan to overthrow the Edo Bakufu by Marubashi Chūya and Yui Shōsetsu was thwarted.
- 1652 (Keian 5, 5th month): Nihon Ōdai Ichiran is first published in Kyoto under the patronage of the tairō Sakai Tadakatsu, daimyō of the Obama Domain of Wakasa Province.
- Nussbaum, Louis-Frédéric. (2005). "Keian" in Japan encyclopedia, p. 503; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, see Deutsche Nationalbibliothek Authority File Archived 2012-05-24 at Archive.is.
- Titsingh, Isaac. (1834). Annales des empereurs du japon, p. 412.
- Screech, T. (2006). Secret Memoirs of the Shogans: Isaac Titsingh and Japan, 1779–1822, pp. 85–89.
- Titsingh, p. 412; n.b., the first copy of this rare book was brought from Japan to Europe by Isaac Titsingh in 1796. Titsingh translated the text from Japanese and Chinese; and his work was then supplemented for posthumous publication by Julius Klaproth. The initial Japanese authorship is confirmed; the precise nengō-dating is confirmed in the same passage -- see Titsingh, p. 406.
- Nussbaum, Louis Frédéric and Käthe Roth. (2005). Japan Encyclopedia. Cambridge: Harvard University Press. ISBN 978-0-674-01753-5; OCLC 48943301
- Screech, Timon. (2006). Secret Memoirs of the Shoguns: Isaac Titsingh and Japan, 1779–1822. London: RoutledgeCurzon. ISBN 978-0-203-09985-8; OCLC 65177072
- Titsingh, Isaac. (1834). Nihon Ōdai Ichiran; ou, Annales des empereurs du Japon. Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691
- National Diet Library, "The Japanese Calendar" -- historical overview plus illustrative images from library's collection
| Era or nengō