Sankin-kotai and the Regional Diffusion of Sword Culture

The Establishment of Sankin-kotai and Its Impact on Sword Culture

In 1635, the third Tokugawa shogun Iemitsu revised the Buke Shohatto (Laws for Military Houses) to require all domain lords to alternate their residence between Edo and their home provinces, typically on a yearly cycle. This "sankin-kotai" (alternate attendance) system was introduced to consolidate the shogunate's political control, but in economic and cultural terms it produced unexpectedly far-reaching effects.

The scale of daimyo processions varied by the domain's rank, but even small domains dispatched retinues of several dozen to several hundred persons, while great domains could mobilize thousands. This was the largest regular movement of people and goods in Edo-period Japan, serving as a critical demand driver for the post-towns and castle towns along every major highway.

The role of sankin-kotai in the relationship with sword-production centers was particularly pronounced. Samurai and retainers participating in the processions routinely required polishing, repair, and fitting work on their swords during the journey, and smiths, polishers, and koshirae craftsmen along the highways flourished by capturing this demand. The fact that major sword-production areas — Mino (Gifu), Echizen (Fukui), Hizen (Saga), Satsuma (Kagoshima) — were situated along the principal sankin-kotai routes was no coincidence; it reflects the relationship between road networks and the geography of craft industry.

Bidirectional Cultural Exchange Between Edo and the Provinces

Sankin-kotai facilitated more than the movement of people — it promoted the bidirectional exchange of information, techniques, and aesthetic sensibility.

From Edo outward to the provinces, the latest styles and techniques of Edo-shinto (new Edo swords) disseminated across the country. Particularly from the later seventeenth century, the slender, sharply defined profile of Kanbun-shinto and its refined hamon expression influenced provincial smiths. As samurai returned to their home domains carrying the latest sword knowledge acquired during their Edo residence, provincial sword culture was continuously updated in alignment with Edo trends.

From the provinces toward Edo, smiths and craftsmen possessing distinctive local traditions migrated to the capital in search of work. Smiths from Hizen who moved to Edo formed the Edo-Hizen tradition, while Satsuma smiths demonstrated their craft in the capital, enriching Edo's sword culture by absorbing regional diversity.

Cascading Effects on Koshirae and Sword-Fitting Industries

The sankin-kotai period produced dramatic growth not only in sword forging but in the koshirae (mountings) and tosogu (sword fittings) industries.

Samurai participating in daimyo processions required fittings appropriate to their rank, and there was constant demand for repair and replacement of fittings damaged or worn on the road. Edo's koshirae and tsuba craftsmen refined their skills under the patronage of daimyo and hatamoto, and the technical level of metalwork rose dramatically during this era.

The lineage of gold-work craftsmen exemplified by the Goto family built their reputation on a foundation of daimyo commissions facilitated by sankin-kotai. The long-term client relationships between the Goto headship and daimyo houses provided the institutional basis for maintaining the highest standards of sword-fitting craftsmanship throughout the Edo period.

Regional Diffusion of Sword Connoisseurship and Appraisal Culture

The samurai class moving between Edo and the provinces through sankin-kotai contributed substantially to the regional spread of sword appraisal knowledge. The expertise of the Hon'ami family and other appraisal specialists was transmitted to daimyo and retainers during their Edo residency, and then carried back to the provinces, fostering the cultivation of sword collecting and connoisseurship culture within individual domains.

Some domains actively positioned sword collecting as a component of their cultural identity, systematically acquiring and maintaining outstanding pieces. The loyalist sword culture of the Mito Tokugawa, the collections of the Kishu Tokugawa, and the famous-sword holdings of the Owari Tokugawa were all, in part, products of the information flows and collecting activities enabled by sankin-kotai.

The End of the System and Its Aftermath

Sankin-kotai was substantially relaxed by the Bunkyu Reforms of 1862 and effectively abolished, symbolizing the decline of shogunal authority and delivering a severe blow to Edo's consumption economy and cultural industries. The sword trade was not immune; the periodic purchasing demand from daimyo — the most important client class — suddenly disappeared, causing a sharp decline in demand for high-grade swords and fittings.

Yet the more than two centuries of accumulated exchange had produced, in each region, distinct layers of sword culture, connoisseurship, and craft tradition that continued to be transmitted as regional diversity in the Meiji-era sword preservation movement and in contemporary Japanese sword culture.