Over a span of 260 years, from 630 to 894, Japanese embassies to Tang China (ken-Tō shi) played a vital role in importing Tang governance and culture to Japan, significantly shaping the political and cultural landscape of an emerging Japanese state with codes of law (ritsuryō). However, the seventeenth embassy during the Jōwa period, fraught with turmoil, marked the final mission to Tang China. Alongside disasters and significant loss of life during the voyage, mysteries persist around Vice-ambassador Ono no Takamura’s refusal to board the ship, the government's insistence on the mission, and the objectives behind dispatching this mission to China.In this volume, Professor Saeki Arikiyo traces the journey from departure to return, focusing on the individuals involved and the prevailing trends of the era. Drawing upon a rich tapestry of historical sources, including records from Shoku Nihon kōki and the accompanying monk Ennin’s Nit-Tō guhō junrei kōki, Arikiyo delves into the arduous journey of this final mission and unravels the intricate motives of the embassy personnel and their encounters in Tang China, offering a comprehensive examination of a transformative chapter in ancient Japanese diplomatic history.