Tainei-ji incident: A coup in Yamaguchi by the military establishment of the Ōuchi clan forces their lord Ōuchi Yoshitaka to commit suicide, and the city is burned.
The Tainei-ji incident (大寧寺の変, Taineiji no Hen) was a coup in September 1551 by Sue Takafusa (later known as Sue Harukata) against Ōuchi Yoshitaka, hegemon daimyō of western Japan, which ended in the latter's forced suicide in Tainei-ji, a temple in Nagato Province. The coup put an abrupt end to the prosperity of the Ōuchi clan, though they ruled western Japan in name for another six years under the figurehead Ōuchi Yoshinaga, who was not related to the Ōuchi by blood.