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] 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):