Tosa Domain

Overview

The Tosa Domain (土佐藩, Tosa-han) was a feudal domain that controlled all of Tosa Province, the southern portion of Shikoku, the smallest of Japan's four main islands. It existed from 1601 to 1871, spanning almost the entire Edo period and ending with the abolition of the han system in the early Meiji period. Its administrative capital was Kōchi, and its rulers were based at Kōchi Castle. For its full history the domain was governed by the Yamauchi clan, a family classified by the Tokugawa shogunate as tozama daimyō (外様大名, tozama daimyō) — lords who had submitted to Tokugawa Ieyasu only after his victory at the Battle of Sekigahara in 1600, and who were therefore treated as outsiders rather than hereditary allies.

History

The domain was established in 1601, in the sixth year of the Keichō era (慶長, Keichō), when Yamauchi Kazutoyo was granted Tosa Province as a reward for his service to Tokugawa Ieyasu. The grant placed the entire province under a single lord, and the Yamauchi made Kōchi Castle the seat of their government. The domain's founding thus falls at the very start of the Edo period, and its institutional life ran without interruption until 1871.

Tosa's distance from the shogunate's heartland shaped its politics. As a tozama domain, it stood outside the inner circle of Tokugawa vassals, and its samurai were divided between the upper-ranking retainers who had come with the Yamauchi from their earlier territories and the lower-ranking gōshi (郷士, gōshi) — rural samurai of Tosa origin who were kept at a distance from power. That internal tension fed directly into the domain's most famous political episode.

In the final decades of the Tokugawa shogunate, Tosa produced a remarkable concentration of figures who shaped national events. Takechi Hanpeita founded the Tosa Loyalist Party, a movement that pressed for the expulsion of foreigners and for reform within the domain. Sakamoto Ryōma, a low-ranking gōshi, became a central broker in the negotiations that produced the Satsuma-Chōshū alliance, the union of two rival domains that made the overthrow of the shogunate possible. Other Tosa men who rose to prominence included Nakahama Manjirō, the shipwrecked fisherman who became one of the first Japanese to visit the United States; Yui Mitsue; Gotō Shōjirō; Itagaki Taisuke; and Nakae Chōmin. The domain's alignment with Satsuma, Chōshū, and Hizen is captured in the shorthand Sat-Chō-Do-Hi, in which "Do" stands for Tosa (土).

After the shogunate fell, the domain was renamed Kōchi Domain (高知藩, Kōchi-han) in the early Meiji period. It was dissolved in 1871 under the abolition of the han system, and its territory became Kōchi Prefecture.

Territory and Influence

Tosa Domain covered the whole of Tosa Province, corresponding to modern Kōchi Prefecture. Its government sat at Kōchi Castle, and the castle town of Kōchi served as the domain's capital. The domain contained subsidiary holdings, among them Tosa-Nakamura Domain and Tosa-Shinden Domain, which were branches of the main house.

The province's position on the Pacific coast of Shikoku left it geographically remote from Edo and from the Kinai core, a remoteness that gave Tosa's samurai unusual freedom to develop their own political ideas. The domain's influence far exceeded its modest economic weight. In the 1860s Tosa was one of the few domains able to speak to both Satsuma and Chōshū, whose feud had blocked unified opposition to the shogunate, and Tosa's mediation helped bring those two domains together. Tosa also advanced a proposal for a bicameral assembly and a written constitution during the last years of the shogunate, an early sign of the domain's later association with the Japanese parliamentary movement. Itagaki Taisuke went on to found Japan's first political party, and the Tosa tradition of popular rights gave the former domain an outsized place in Meiji politics.

The Name in Japanese

The Japanese name is 土佐藩, read とさはん in kana and written Tosa-han in romaji.

• 土 (と, to) — "earth" or "soil". This is the first character of Tosa, the old province name.
• 佐 (さ, sa) — "assist" or "help". Together with 土 it forms 土佐, the province that corresponds to modern Kōchi Prefecture.
• 藩 (はん, han) — "domain" or "clan territory". In the Edo period this character denoted a lord's hereditary fief, a territory governed by a daimyō under the shogunate. The word is a Japanese coinage; the character originally meant a fence or boundary, and by extension a defended territory.

So 土佐藩 means, literally, "the domain of Tosa". The same 藩 appears in the names of every other Edo-period domain, which is why the system is called the han system. Readers will also encounter 高知藩 (Kōchi-han), the name the domain carried briefly in the early Meiji period, built from 高知, the city name, plus the same 藩.

Legacy

Tosa Domain's most durable legacy is its people. Sakamoto Ryōma is one of the most widely commemorated figures in Japanese history, credited with the alliance that ended the shogunate; his birthplace and memorials draw visitors to Kōchi to this day. Itagaki Taisuke carried Tosa's reformist impulse into the Meiji era as a leader of the Freedom and Popular Rights Movement. Nakahama Manjirō's account of his time in America became a source of knowledge about the outside world at a moment when such knowledge was scarce.

The domain itself ended in 1871, when the abolition of the han system replaced feudal territories with prefectures. Its lands became Kōchi Prefecture, which preserves the province's boundaries and its name in a new form. Kōchi Castle remains standing as the domain's central monument, and the Yamauchi clan's former seat is now a public site in the city that served as the domain's capital for more than two and a half centuries.