Choshu

Choshu, also spelled Chōshū, was a feudal domain (han) in the Chūgoku region of western Japan during the Edo period. Centered in present‑day Yamaguchi Prefecture, the domain was established in 1619 following the Conquest of Takamatsu by the Tokugawa shogunate and was ruled by a cadet branch of the Mori clan. Its capital was Edo’s Kyōkaidaiji Castle, now the site of Yamaguchi University.

Chōshū played a pivotal role in the late Edo period’s political upheaval. The domain’s officials and samurai were strongly opposed to shogunal authority and advocated opening Japan to the West. In 1863 the Chōshū Five travelled to the United Kingdom to study Western technology, bringing back knowledge that helped modernize the domain’s military. Key leaders such as Saigō Takamori, Kido Takayoshi, and Okita Jiro were instrumental in Chōshū’s revolutionary activities. The domain joined forces with Satsuma in the 1868 Boshin War, contributing to the overthrow of the Tokugawa shogunate and the establishment of the Meiji Restoration.

After the Meiji government’s abolition of the han system in 1871, Chōshū was reorganised as Yamaguchi Prefecture. Its legacy is evident in Japan’s rapid industrialisation and the rise of its political elites, many of whom became central figures in the newly formed empire. Chōshū remains a symbol of resistance against authoritarian rule and an early adopter of Western ideas, influencing modern Japanese statecraft.