Japanese Sword Export Routes in the Muromachi and Sengoku Periods: Trade to Ming China, Korea, and Southeast Asia

Why did Muromachi and Sengoku period swords flow overseas?

From the 15th to 16th centuries, Japan was one of East Asia's leading sword-exporting nations. While illegal distribution by wakō often receives attention, in reality it was the official kanjō trade routes managed by the shogunate that formed the backbone of large-scale exports. This article explains both the official and unofficial distribution channels and estimated export volumes, as well as the demand structures in Ming, Korea, and Southeast Asia—the three regions that received these exports.

Swords in kanjō trade and Japan-Ming trade

The kanjō trade concluded between the Muromachi shogunate and the Ming court (1404–1547) was a state-level transaction in which Japan periodically sent tributary ships to Ming and received copper coins, raw silk, and ceramics in return. "Swords" were consistently listed as the foremost of these trading goods.

In Ming documents such as the "Daming Huitian," Japanese swords are listed as items imported under such categories as "nagiata," "tachi," and "armor," sometimes numbering in the thousands per voyage. According to records of the Ming mission ship of 1483, 36,000 swords, sulfur, and copper are enumerated as the main cargo. The figure of "36,000 swords" suggests that the vast majority consisted of mass-produced "kazuuchimono" manufactured on large orders from production centers such as Bizen, Mino, and Sagami.

Japanese swords are said to have had lower procurement costs compared to their purchase prices within Ming, and this price differential is believed to have been the economic motivation for the shogunate and merchants to continue sword exports. Additionally, Japanese swords were highly valued as practical swords in both Ming and Korea due to their superior forging techniques, and the fact that they fulfilled actual demand beyond mere gift-giving is pointed out as another reason why exports continued over such a long period.

Exports to Korea—the reality of Japan-Korea trade

Between Korea and Japan, "Japan-Korea trade" was conducted with the mediation of the Tsushima domain (the Sō clan). Records of sword imports from Japan appear frequently in the "Annals of the Joseon Dynasty" of the 15th century. The demand on the Korean side was primarily for tachi intended for ritual and formal wear, and there was a tendency to seek high-quality swords bearing the signatures of master smiths.

While it is difficult to estimate the volume of sword exports via Tsushima, it is thought that during the period after the Kakitsu Treaty of 1443, when annual tributary ships expanded to around 50 vessels per year, several hundred swords may have been loaded on each ship. For the Goryeo and Joseon warrior class (muban), Japanese swords were recognized as imported goods of superior quality and prestige.

The sword trade between Japan and Korea was not limited to individual commercial transactions but also had a strong aspect of being conducted as part of diplomatic rituals. The missions conducted by annual tributary ships were merchant vessels that simultaneously served as diplomatic envoys, and the swords played a role as tribute and gifts carried by these envoys. Against this background, it is thought that some of the Japanese swords that reached Korea were preserved not merely as commodities but as items symbolizing diplomatic relations.

Diffusion to Southeast Asia—the route via Ryukyu

The Ryukyu Kingdom (present-day Okinawa) was a major hub of Southeast Asian trade in the 15th and 16th centuries. It thrived on intermediary trade, purchasing swords, fans, and sulfur from Japan and reselling them to Siam (present-day Thailand), Java, Malacca, and Luzon (the Philippines).

In the "Rekidai Houan" (a compilation of Ryukyu diplomatic documents), there are multiple records of transactions involving Japanese swords recorded as "watō." These documents show that Japanese swords circulated not only as weapons but also as gifts and ritual items.

The intermediary trade via Ryukyu was made possible due to Ryukyu's unique position of maintaining formal diplomatic relations with both Ming and Japan. The flow of purchasing swords from production centers within Japan and reselling them to port city-states throughout Southeast Asia functioned as part of the maritime trading network operated by Ryukyu merchants, with swords positioned as one of the main trading goods alongside sulfur and fans.

Unofficial distribution—kazuuchimono and local modification

After 1547, when kanjō trade ceased, some daimyo and merchants attempted direct exports as "free trade." The goods in circulation during this period included not only standard kazuuchimono made by specialist blacksmiths, but also "shirasaya export," in which only the blade was exported and the fittings were made locally.

Among Japanese swords discovered in Southeast Asia, some have local-style hilts and scabbards while the blades clearly show Bizen and Mino forging characteristics. This is evidence of "local modification and circulation," demonstrating that the blade itself functioned as a commodity.

The impact of exports on sword-forging centers

The overseas demand of the Muromachi and Sengoku periods directly impacted the production systems of domestic sword-producing centers. In Bizen Osafune, workshops engaged in mass production for export proliferated, and so many swords from this period survive that modern researchers classify them into periods such as "Ōei Bizen" and "Daiei Bizen."

This large-scale export led to "bipolar quality differentiation." While kazuuchimono for export were mass-produced items with simplified processes, commissioned swords for shoguns and daimyo were crafted as masterpieces employing cutting-edge techniques. This bipolar structure has historical parallels to the modern divergence between "modern swords" and "traditional swords."

Perspectives on export history in modern collecting

Considering the export history of the Muromachi and Sengoku periods, there are several perspectives that are useful when evaluating existing Japanese swords.

• Many of the swords that went overseas were kazuuchimono and may have different production backgrounds from swords that remained domestically.

• As exemplified by cases where local fittings were remade for exported blades, there are historical instances where the provenance of the blade and the fittings do not necessarily correspond.

• Precisely because of this complexity in provenance, certification by the NBTHK (Society for Preservation of Japanese Art Swords) to authenticate the blade itself, its maker, and period is of critical importance in current transactions.

• The fact that production systems varied by region and period means that even swords from the same "Muromachi period" had quality variations depending on the workshop and patron, making authenticated genuine works a key consideration when selecting pieces.

These are not so much the historical facts of export themselves, but rather how that history connects to current sword evaluation—perspectives positioned as one guide when considering purchase and collection.

Conclusion—industrial history of medieval Japanese swords revealed by overseas distribution

The export of Japanese swords during the Muromachi and Sengoku periods was not merely an "outflow of swords abroad," but also evidence of industrial history showing how Japan was integrated into the East Asian economy of the time. The export of tens of thousands of swords annually to Ming via kanjō trade, the trade in formal tachi with Korea via Tsushima, and the resale to Southeast Asia via the Ryukyu route—these distribution networks supported the Japanese sword industry of the 15th and 16th centuries and were instrumental in developing domestic production centers to a scale beyond modern imagination. When we view swords in light of this expansive circulation, we can more concretely understand the significance of carefully examining the provenance and production background of each individual sword.