Yoshiaki succeeded his father Sagara Yoshiaki. He refused a request by Shimazu Yoshihisa in 1581 to allow the Shimazu unhindered transit through the Sagara domain. In consequence, Yoshihisa besieged Yoshiaki at Minamata Castle and forced him to commit suicide.
References
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005