Daidō (大同) was a Japanese era name (年号, nengō, lit.
"year name") after Enryaku and before Kōnin.
This period spanned the years from May 806 through September 810.
[1] The reigning emperors were Heizei-tennō (平城天皇) and Saga-tennō (嵯峨天皇).
[2]