Kaei (嘉永) was a Japanese era name (年号, nengō, lit.
"year name") after Kōka and before Ansei.
This period spanned the years from February 1848 through November 1854.
[1] The reigning emperor was Kōmei-tennō (孝明天皇).
The era name is derived from an aphorism in the Book of Song: "A wise Emperor receives much help, One who esteems comfort is on the outside" (思皇享多祐、嘉楽永無央).