Yoshimune officially succeeded his father Sorin in 1576 and authorized the campaign aimed at driving the Shimazu from Hyûga province. After the Ôtomo army was defeated at Mimigawa (1578), Yoshimune was occupied with keeping increasingly rebellious vassals in line. Taking advantage of the death of Ryûzôji Takanobu at the hands of the Shimazu, Yoshimune sent an army into Ryûzôji territory, though he accomplished little. When the Shimazu invaded Bungo and Toyotomi Hideyoshi sent an expeditionary force to Funai (led by Chosokabe Motochika and Sengoku Hidehisa), Yoshimune, against Chosokabe's advice, insisted on taking the field to relieve Toshimitsu castle, then under attack by the Shimazu. The result of this ill-concieved adventure was the January 1587 battle of Hetsugigawa, where Yoshimune and his allies were soundly defeated. Yoshimune fled back to Funai, which he soon had to abandon to the Shimazu. After Hideyoshi's main army descended on Kyushu and drove the Shimazu back to southern Kyushu, Yoshimune was confirmed as daimyô of Bungo. He led 6,000 men to Korea as part of Kuroda Nagamasa's division but displayed cowardice in the fighting around Pyong'yang: learning of a sizable Chinese force moving into the area, Yoshimune disregarded Konishi Yukinaga's call for aid and retreated. This incurred Hideyoshi's wrath and the Ôtomo domain was forfeited. Yoshimune sided with Ishida Mitsunari during the Sekigahara Campaign and was exiled afterwards. He died on 2 September 1605, the last lord of the Ôtomo family. Yoshimune had been baptized in 1574 as Constantinho but was not as sympathetic to the missionaries as his father had been.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005