Born in Yamaguchi, Suo, as a son of Ouchi Yoshioki. The Ouchi were western leaders rich from Ming trade and culture. He grew up watching his father's Kyoto politics.
On his father's death he succeeded, backed by Sue Okifusa and other elders, seeking to hold and expand Ouchi lands. He valued both arms and letters and treated courtiers and Zen monks kindly.
He invited courtiers, renga poets and Zen monks, making Yamaguchi a cultural mirror of Kyoto. He favored elegant learning and increasingly prized letters over war.
He resumed tally ships halted after the Ningbo Incident, seeking to restore trade profits. Ming goods gathered in Yamaguchi; Ouchi culture peaked.
He marched against the Amago of Izumo and the next year besieged Gassan Toda, but failed and withdrew amid kokujin defections. Preference for culture over war began to anger retainers.
He besieged Amago Haruhisa's Gassan Toda with a large army, but the long war strained food and morale. Losses on withdrawal deepened retainers' distrust of Yoshitaka.
Around this time firearms reached Tanegashima. Yoshitaka's reign stood at the door of Sengoku technical change; news of new weapons began to spread in the west.
Senior vassal Sue Takafusa pushed military priority against Yoshitaka's civil line. Adoption disputes also widened an irreparable house rift.
He met the missionary Francis Xavier and allowed Christian preaching in Yamaguchi. He is said to have granted the Daido-ji temple site, known as a cosmopolitan daimyo.
Retainer Sue Takafusa (Harukata) rose in arms; Yoshitaka took his own life at Tainei-ji in Nagato. Tension between cultural rule and senior vassals is cited. Ouchi zenith was badly shaken.
Ōuchi YoshiokiAmago TsunehisaSue Harukata (Takafusa)Ryuzoji TakanobuKikkawa MotoharuFrancis XavierMōri Motonari
Saitō DōsanTaigen SessaiMōri MotonariFrancis XavierMatsunaga HisahideHōjō UjiyasuImagawa YoshimotoImai Sōkyū
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.