Saga Dies and the Jōwa Incident Changes the Crown Prince

The retired Emperor Saga died in 842. The succession then linked the descendants of Saga and his brother, the former Emperor Junna: Junna's son Tsunesada was crown prince under the reigning Emperor Ninmyō, Saga's son. Saga's death removed an influential senior member of the imperial household.

Soon afterward, officials reported an alleged plot involving people around Tsunesada, including the courtier and calligrapher Tachibana no Hayanari. The government arrested and punished members of the crown prince's circle. Tsunesada lost his position; Ninmyō's son Michiyasu became crown prince instead. Michiyasu's mother was a sister of Fujiwara no Yoshifusa, whose family now gained a closer connection to the designated succession.

Hayanari was sent into exile and died on the way. The accusations and punishments are more securely recorded than the full existence or design of the alleged conspiracy. Saga's death preceded the change and altered the household's balance, but the investigation and new appointments were actions of the government that survived him.