Tenchō (天長) was a Japanese era name (年号, nengō, lit.
"year name") after Kōnin and before Jōwa.
This period spanned the years from January 824 through January 834.
[1] The reigning emperors were Junna-tennō (淳和天皇) and Ninmyō-tennō (仁明天皇).
[2]