Ten'en (天延) was a Japanese era (年号,nengō, "year name") after Tenroku and before Jōgen. This period spanned the years from December 973 through July 976. The reigning emperor was En'yū-tennō (円融天皇).
February 6, 973Ten'en gannen (天延元年): The new era name was created to mark an event or a number of events. The previous era ended and a new one commenced in Tenroku 4, on the 20th day of the 12th month of 973.
Events of the Ten'en era
May 28, 973 (Ten'en 1, 24th day of the 4th month): A fire broke out in a Minamoto compound located near the Imperial Palace. The fire could not be contained; and more than 300 houses were reduced to cinders. The guard was doubled around the Emperor's residence.