Born a son of Amago Kiyosada, deputy shugo of Izumo. The Amago rose from Kyogoku vassals toward independence, growing from Gassan Toda Castle.
Clashing with the Kyogoku shugo, he was once driven from Toda, tradition says. By guile and persistence he regained the castle and real power in Izumo. Tales of his comeback appear in later chronicles.
He largely subjected Izumo kokujin and transformed from deputy shugo into a de facto Sengoku daimyo, checking Ouchi influence and building a firm San'in base.
He pushed into neighboring Hoki and Inaba; tradition says Amago armies were feared like clouds. Organizing kokujin and patient diplomacy and war were his strengths.
He fought Ouchi Yoshioki in Iwami and Aki. Advance and retreat continued; a long rivalry over San'in and Sanyo hegemony began.
He intervened in Aki kokujin quarrels and dealt with Mori Motonari and others. Later the Mori would survive between Ouchi and Amago; for now Amago pressure was strong.
Influencing Izumo, Oki, Hoki, Inaba and Iwami, the Amago reached their peak. Toda was famed as hard to take, and under Tsunehisa's seasoned lead the house held together.
He passed the headship to his grandson Haruhisa and retired as guardian. Confrontation with Ouchi Yoshitaka continued; even in old age he remained the strategic center.
He besieged Mori Motonari's Yoshida-Koriyama with a large force but failed against Ouchi relief and withdrew. Amago momentum began to fade, leaving tasks for the next generation.
He died at Gassan Toda at eighty-four, having built Sengoku daimyo power in Izumo. Soon after, Yoshitaka's attack on Toda began and the Amago faced a severe trial.
Ōuchi YoshiokiMōri MotonariŌuchi Yoshitaka
Hōjō Sōun (Ise Sōzui)Hojo UjitsunaSaitō DōsanTaigen SessaiMōri MotonariFrancis XavierŌuchi YoshitakaMatsunaga Hisahide
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.