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.[1] The reigning emperor was Go-Kōmyō-tennō (後光明天皇).[2]
Change of era
1648Keian 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.[2]
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.[3]
^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.
