Jōgan

Change of era

• February 7, 859 Jōgan gannen: The new era name was created to mark an event or series of events. The previous era ended and the new one commenced in Ten'an 3, on the 25th day of the 4th month of 859.

  Events of the ''Jōgan'' era

• 859 : All New Year's festivities were suspended because of the period of national mourning for the death of Emperor Montoku.
• 864 : Mount Fuji erupted during 10 days, and it ejected from its summit an immense quantity of cinders and ash which fell back to earth as far away as the ocean at Edo bay. Many people perished and a great number of homes were destroyed. The volcanic eruption began on the side of Fuji-san closest to Mount Asama, throwing cinders and ash as far away as Kai Province.
• 869 : Yōzei was born, and he is named Seiwa's heir in the following year.
• July 9, 869. The 869 earthquake and tsunami devastates a large part of the Sanriku coast near Sendai.
• 876 : In the 18th year of Seiwa-tennō 's reign, the emperor ceded his throne to his five-year-old son, which means that the young child received the succession. Shortly thereafter, Emperor Yōzei formally acceded to the throne.