The Year of Two Embassies: Ieyasu’s 1610 Overtures to China and Korea

In January 1610, the Portuguese carrack Madre de Deus burned and sank in Nagasaki harbour. Her captain, André Pessoa, chose to blow her magazines rather than surrender to the samurai fleet that had surrounded her. Chinese silk worth a fortune went to the bottom of the bay, along with some six hundred thousand cruzados in Japanese silver and the patience of every Portuguese merchant who still believed the Nanban trade could be conducted on European terms.

Two months later, Father João Rodrigues, Ieyasu’s former commercial broker, the Jesuit interpreter who for more than a decade had handled the shogunate’s most sensitive commercial negotiations, was packed onto a ship and exiled to Macau. His successor in Ieyasu’s confidence was already in place: an English Protestant pilot named William Adams, who did not carry a cross and did not intend to convert anyone.

At roughly the same time, a letter went out from the Tokugawa shogunate to the Ming mandarins at Canton, proposing the resumption of direct Chinese trade with Japan. And somewhere between the rocky island of Tsushima and the Korean port of Pusan, a walled compound was being finished for Japanese merchants who, following the first formal treaty with Korea in twenty years, would shortly be permitted to resume a severely restricted commerce suspended since the armies of Toyotomi Hideyoshi rolled across the peninsula in 1592.

To contemporaries, 1610 did not look like a turning point in East Asian history. No single event dominated it. Ieyasu, now sixty-seven, had been officially retired for five years, having handed the shogunal title to his son Hidetada while retaining every meaningful lever of power from his retirement palace at Sumpu. The Osaka campaigns that would exterminate the Toyotomi were still five years away; the great expulsion edict against the missionaries was still four years off.

But viewed from the right angle, 1610 is the year in which Ieyasu achieved something that neither Oda Nobunaga nor Hideyoshi had managed: a foreign policy. Not a war, not a mission, not a commercial accident, but a deliberate, multi-front, long-horizon strategy for how Japan would engage with the world beyond its shores. Its three pillars were breaking the Portuguese monopoly on Chinese silk that the Nau do Trato carried from Macau each year; rehabilitating Japan’s reputation with the continental powers whose rulers Hideyoshi had so recently proposed to depose; and building a diplomatic architecture of treaties, trading posts, and protocols that was entirely Japanese-made and depended on no European intermediary.

The Legacy Problem

To understand why Ieyasu needed an East Asian foreign policy in 1610, you have to understand what he had inherited.

The man who preceded him as the most powerful figure in Japan had spent the final decade of his life attempting to conquer China.

Toyotomi Hideyoshi’s invasions of Korea, the Bunroku campaign of 1592 and the Keichō campaign of 1597, had been, by any rational accounting, the greatest military catastrophe Japan would experience before the twentieth century. Six years of fighting in which Japanese armies, after the initial explosive advance, had been ground down by Korean militias, Chinese relief armies, and the turtle ships of the incomparable Admiral Yi Sun-sin. The Korean peninsula had been wrecked. An estimated fifty to sixty thousand Korean civilians had been rounded up and shipped back to the archipelago as slaves, potters, artisans, women, children, some of whom ended up in Jesuit-licensed cargoes bound for Macau and Goa. Hideyoshi himself had died in 1598 with his armies stranded on a foreign shore, and his political order had collapsed within two years of his death.

From the Joseon court in Seoul, and from the mandarins in Beijing, Japan looked like what it had in fact behaved as: a barbarian power that had launched an unprovoked war of conquest against the civilised world and had been chastened only by military defeat.

Formal diplomatic relations with China had been broken a lot longer than that. Since the middle of the sixteenth century, the Ming dynasty had maintained its haijin, the maritime prohibition, against all direct contact with Japan, a policy originally driven by the depredations of the wakō pirates whose bases along the Kyushu coast had terrorised the Chinese seaboard for generations. Hideyoshi’s invasions merely confirmed a diagnosis the Ming had already made.

The practical consequence was that every scrap of Chinese silk, porcelain, and medicine that reached Japanese markets did so through middlemen, and the most important of these middlemen, by an almost embarrassing margin, were the Portuguese operating from their rented enclave at Macau. Their annual carrack carried raw Chinese silk up the coast to Nagasaki, traded it for Japanese silver at a spectacular markup, and returned to do it all again the following year. The Jesuits, who depended on the trade’s profits to fund their mission, negotiated the silk contracts at the Nagasaki end and took a cut.

Ieyasu, from the moment he consolidated power after Sekigahara, had understood two things about this arrangement. The first was that it was enormously profitable for the Portuguese and enormously expensive for Japan. The second was that it placed the economic welfare of his realm in the hands of a foreign power whose religious agenda he distrusted and whose loyalty he could not command. By 1610, he had been working on a solution for nearly a decade.

The Canton Message

The Chinese track was, on the surface, the simpler of the two.

In the course of 1610, Ieyasu dispatched a diplomatic message directly to the authorities at Canton, the great southern port through which, by longstanding Ming practice, all foreign trade with the empire was channelled. The message did not attempt the grand gesture of a tributary embassy to the imperial capital. Ieyasu was too shrewd to propose something Beijing would have been constitutionally incapable of accepting; an official Japanese embassy turning up at the Ming court in 1610 would have been met with the same icy hostility that had greeted the last Japanese envoys half a century earlier.

Instead, the message was pitched at the level of regional commerce. It was addressed to the civil and military authorities of Guangdong province, and it offered, in effect, a commercial prospectus designed to entice private Chinese merchants back to Japanese waters. The terms were striking. Chinese merchants were warmly invited to trade in any province, any island, any inlet of the Japanese archipelago. Unlike the Portuguese, confined, by this point, to Nagasaki and a handful of other tolerated ports, the Chinese would enjoy complete freedom of movement. And if any Japanese subject harassed or molested a Chinese trader in the course of his business, the Japanese troublemaker would be promptly punished by the shogunate itself.

This was extraordinary. Ieyasu was offering, to the subjects of a nation with which Japan had no diplomatic relations whatsoever, a degree of legal protection he had been reluctant to extend even to the Europeans who had built his trade networks. The calculation was clear: the Portuguese carried Chinese silk on Portuguese ships, taking a middleman’s profit at every stage. Chinese ships carrying Chinese silk would cut the Portuguese out entirely, and the silver that currently flowed to Macau would flow directly to merchants in Fujian and Guangdong instead, merchants with no interest in proselytising, no entanglement with Spanish Manila, and no alternative to the Japanese silver supply that was, in 1610, the largest in the world.

It was a beautifully conceived initiative. It did not quite work.

The problem was not the Canton mandarins, who appear to have been willing to wink at the arrangement to some extent, private Chinese trade to Japan did indeed increase during the Tokugawa decades, much of it technically illegal under Ming law but tolerated by local officials happy to pocket the customs revenue. The problem was that Ieyasu had asked for something the Ming government could not afford to grant. A formal, state-sanctioned resumption of Sino-Japanese diplomatic relations would have required an imperial decision at the highest level, and by 1610 the Wanli Emperor and his court had rather more pressing concerns.

Those concerns had a name. In the far northeast, beyond the Great Wall, a Jurchen chieftain named Nurhaci had been consolidating the tribes of Manchuria into a confederation that would declare itself a dynasty in 1616, defeat successive Ming armies through the 1620s and 1630s, and ultimately, under his grandson, in 1644, storm Beijing, hang the last Ming emperor from a tree on Coal Hill, and proclaim the Qing dynasty. In 1610, the catastrophe was still a generation away, but the shadow was already visible. The Ming court’s attention, its resources, and its remaining competence were all drifting northward.

Japan, by comparison, was a minor commercial nuisance. The Canton message achieved what it could: a quiet tolerance of private Chinese trade that expanded through the seventeenth century and would, after the Ming collapse, become the single largest channel of foreign commerce into Nagasaki. What it did not achieve was formal diplomatic rehabilitation. Japan would not sign a treaty with China. Japan would not exchange ambassadors with Beijing. For the next two and a half centuries, the Chinese connection would be conducted exclusively through private merchants operating in a quasi-legal grey zone, a workable arrangement, and an enormously profitable one, but not the formal parity that Ieyasu had wanted.

For formal diplomacy, he would have to look elsewhere. He looked to Korea.

The Shape of the Island

The Korean track was, in principle, far more difficult. Korea had actually been invaded. Korean cities had been burned, Korean civilians enslaved, Korean nobles dragged across the strait in chains. Any Korean diplomat willing to negotiate with Japan in the decade after Hideyoshi’s death had to explain to his own court why he was prepared to deal with the nation that had committed these atrocities. That any diplomacy happened at all was down to the peculiar geography of a single island.

Tsushima sat in the middle of the Korea Strait, closer to the Korean port of Pusan than to any major Japanese city. It was rocky, mostly unfarmable, and populated by a clan, the Sō, whose entire economic existence had depended, for four centuries, on privileged trading access to Korea. When Hideyoshi’s invasions severed that access, Tsushima had not simply lost an income stream; it had lost its means of subsistence. The Sō clan, under Sō Yoshitoshi, emerged from the wars of the 1590s with a single overriding political objective: the restoration of Korean trade, at any cost, by any means.

The means they chose were remarkable.

From roughly 1599 onwards, the Sō began what can only be described as a decades-long campaign of diplomatic fraud aimed at both the Tokugawa shogunate and the Joseon court. The problem they faced was structural. Korea demanded that Japan make the first move, that the Tokugawa formally request peace, acknowledging defeat. Ieyasu, for reasons of prestige and domestic politics, absolutely refused. Korea additionally demanded that any Japanese correspondence use the title “King of Japan” and date its letters by the Chinese calendar, both of which implied that Japan was a subordinate vassal within the Ming tributary order. The Tokugawa would not accept this either. The real diplomatic positions of the two governments were mutually incompatible.

The Sō solved the problem by inventing diplomacy that did not exist.

In 1606, the Sō chancery, probably with the knowledge and connivance of the Zen monks who served as its diplomatic draftsmen, composed a letter purporting to come from “the King of Japan, Minamoto no Ieyasu”, using the Ming calendar, requesting peace with the Joseon court. The letter was a fabrication from top to bottom. Ieyasu had never written it and would have been horrified to learn of its contents. The Korean court received it with some suspicion but decided, pragmatically, to accept it at face value. In 1607, Seoul dispatched a formal “return embassy”, the first of the Swaehwan sa, or “prisoner retrieval missions”, to Japan.

Now the Sō had a new problem. The Korean envoys were carrying a letter from King Seonjo that replied, using Korean protocols, to the forged letter “King Ieyasu” had sent. If the envoys reached Edo or Sumpu and handed this letter to the Tokugawa, the entire fraud would be exposed, and the consequences, for the Sō, would be spectacular.

The Sō intercepted the letter en route. Somewhere between Tsushima and the Japanese mainland, the Korean envoys’ diplomatic correspondence was quietly substituted with a sanitised replacement, rewritten by Sō clerks, which removed all references to the Chinese calendar, the tributary system, and the problematic titles. The version handed to Hidetada in Edo and to Ieyasu at Sumpu bore only a passing resemblance to the document the Korean king had actually composed.

Everyone in Edo thought they had received the Korean king’s letter. They had in fact received a forgery of a reply to a forgery.

The embassy was, nonetheless, a diplomatic success on its nominal terms. The Koreans were received with ceremony. Hidetada presented them with gifts. They returned to Seoul with roughly 1,240 to 1,418 repatriated Korean captives, a fraction of the total taken during Hideyoshi’s wars, but a visible gesture of goodwill.

The fraud continued. In 1617, when the Korean court wished to send congratulations on the fall of Osaka, the Sō fabricated the congratulatory letter themselves before the Koreans had even drafted it. When the bakufu drafted its formal reply, addressing the Korean king using the neutral title “State of Japan” (Nihon kokushu), the Sō counterfeiters inserted the character for “King” to satisfy Korean protocol. In 1624, when a third Korean embassy arrived to congratulate the new shogun Iemitsu, the Sō again altered the bakufu’s outgoing correspondence by a single pen stroke, upgrading Nihon kokushu to Nihon kokuō, “King of Japan”, before the Koreans saw it.

For twenty-nine years, the diplomatic relationship between the Tokugawa shogunate and the Joseon court was a shared hallucination, maintained by a small clan of Japanese clerks on a barren island. Both sides believed they were conducting formal diplomacy on their own terms. Neither was. The peace was real. The documents were not.

The Monk and the Shogun

Into this landscape of strategic deception walked one of the more arresting figures of the Nanban period: a Korean Buddhist monk named Yujong.

Yujong, also known as Samyeongdang, “Hall of the Four Illusions”, was not a diplomat. He was a senior Sŏn (Zen) master who had distinguished himself during the invasions by organising monastic resistance to the Japanese armies, a role for which he was widely celebrated in Korea as a patriotic hero. When the Joseon court cast around in 1604 for an envoy to send to Japan to probe Tokugawa intentions regarding prisoner repatriation, Yujong was an inspired choice. He was a monk, which gave him standing in religious circles that transcended diplomatic protocol. He had fought the Japanese, which gave him domestic credibility. And he spoke Chinese, the shared literary language of East Asian elites, which meant he could communicate with any educated Japanese counterpart through brush-and-paper conversation.

He arrived in Tsushima in 1604. Sō Yoshitoshi, the head of the forgery conspiracy, in his other professional capacity, personally escorted him across the strait and up through Japan to an audience with Ieyasu himself.

The meeting that followed has had its details embellished by Korean biographical tradition, but its practical outcome is not in dispute. Yujong returned to Korea in 1605 with something between 3,000 and 4,390 liberated Korean captives, by far the largest single repatriation of the entire Nanban period, arranged through the combined efforts of the Sō clan (who purchased captives from Japanese slave-holders) and the monk’s own direct negotiations with Ieyasu’s court.

The full arithmetic of the repatriations is bleak and worth stating plainly. Of the estimated fifty to sixty thousand Koreans taken captive during Hideyoshi’s invasions, approximately 7,500 were ever returned, a figure settled by the twentieth-century Japanese historian Naitō Shunpo. The missions of 1600 through 1605, culminating in Yujong’s extraordinary haul, accounted for most of that number. Later missions brought back smaller groups: the formal 1607 embassy returned some 1,240 to 1,418 captives, the 1617 mission following Osaka produced 321, and the 1624 mission only 146, including three infants born in Japanese captivity. By the 1636–1643 window, the figure had collapsed to about twenty-five in total; the missions had by then formally rebranded themselves as tongsinsa, “communications embassies”, acknowledging that the prisoner-repatriation function was effectively over. Most of the original captives had either died, assimilated into Japanese society (particularly the celebrated Korean potters of Satsuma and Karatsu, whose descendants still produce pottery in Kyushu today), or, in a reality that Joseon chroniclers found painful to record, actively refused repatriation, having heard rumours that returnees were being treated as polluted by their captivity and denied proper social reintegration in Korea.

The Treaty of Giyu

By 1609, the groundwork was complete. Enough captives had been returned, enough forged letters exchanged, enough ceremonial embassies passed between Edo and Seoul, for the two governments, or rather, the Sō family’s versions of them, to conclude a formal commercial treaty.

The Treaty of Giyu was signed in 1609. The Korean negotiator was Yi Chi-wan. The Japanese side was represented by a Zen priest named Genshō, who served as the Sō chancery’s senior diplomatic draftsman, and an agent named Yoshimas. The terms, from a Japanese perspective, were brutal.

Japanese merchants would be confined to a single Korean port: Pusan. The three ports that had been open before Hideyoshi’s wars, Pusan, Jepo, and Yeompo, would not all be restored; the Japanese negotiators pleaded, and the Koreans refused. Within Pusan, Japanese traders would be further confined to a walled compound known as the Waegwan, “Japan House”, on the outskirts of the city. The compound was, in its operating logic, a prototype for the arrangement the Dutch would accept at Dejima a generation later: foreign commerce contained within a physical perimeter, its participants forbidden to travel inland, its operations observed at all times by local officials.

The quotas were stringent. The Sō family was permitted to dispatch no more than twenty ships to Korea per year. Diplomatic agents of the shogun were limited to a maximum residence of 110 days; agents representing other daimyō to 85 days; special commercial agents to 50. Japanese envoys were explicitly forbidden to travel inland to Seoul, a break with the pre-war convention under which Japanese embassies had sometimes reached the Korean capital.

The Japanese side accepted all of it. They had no leverage. They had invaded, they had lost, they had sued for peace through forged letters, and they were now being told, with icy Confucian precision, exactly how subordinate their position was going to be.

And yet the treaty worked. For the next 260 years, through the entire Tokugawa period, through the rise and fall of the Qing, through the Meiji Restoration, the Pusan Waegwan remained the sole conduit for legal commerce between Japan and Korea. The Sō clan grew rich on the proceeds. Korean ginseng, medicinal herbs, and raw silk flowed east. Japanese silver, copper, and manufactured goods flowed west. A diplomatic architecture built on forged letters and humiliating quotas proved to be one of the most durable international relationships in early modern East Asia.

The 1610 envoys that followed the treaty were, in effect, the choreography of its implementation: delegations from the Sō, under shogunal authority, making the short crossing from Tsushima to Pusan to register the new reality and begin its operations.

The Collapse of the Shadow

The Sō forgeries could not last forever. In 1635, they didn’t.

The collapse came through internal betrayal. Yanagawa Shigeoki, a senior retainer whose family had been central to the forgery operation for three generations, fell out with his lord Sō Yoshinari, grandson of the Yoshitoshi who had escorted Yujong to Ieyasu, over matters of domestic politics. Yanagawa did what Japanese political culture generally punished severely: he denounced his daimyō to higher authority. He went to the shogunate, laid out decades of forged letters and counterfeited shogunal seals, and demanded that Sō Yoshinari be stripped of his lands and his clan destroyed.

The bakufu investigated. The evidence was overwhelming. The entire diplomatic correspondence with Korea for the previous three decades had, in large part, been produced by the Sō chancery rather than by the Japanese government.

By any strict reading of Tokugawa law, the Sō were finished. Forging a shogunal seal was a capital offence of the highest order. The scandal should have taken down the clan and stripped Tsushima of its privileges.

It did not. Shogun Iemitsu, no sentimentalist, and no friend of institutional irregularity, looked at the situation and calculated. Exposing the forgeries publicly would humiliate both the Tokugawa and the Joseon court. It would raise questions about the legitimacy of every diplomatic exchange conducted since 1606. It might even unravel the carefully constructed peace itself, pushing Korea back toward estrangement at a moment when Iemitsu was sealing the country shut against the Iberians and needed his continental flank stable.

Iemitsu ruled for the Sō. The retainers who had personally carried out the forgeries were executed or exiled. The Sō clan escaped with a reprimand and retained their position as the bakufu’s designated intermediary with Korea. But the shogunate did not simply ignore what it had learned. From 1635 onwards, the Iteian system was established: a rotating supervisory office staffed by Zen monks from Kyoto’s Gozan network, dispatched to Tsushima to oversee all Japanese-Korean correspondence and ensure no further unauthorised creativity occurred. The Sō kept their monopoly. They lost their autonomy.

The shadow diplomacy of 1606 to 1635 remains one of the strangest episodes in early modern international relations: a peace between two major East Asian powers, maintained for a generation by the deliberate fraud of a small clan of intermediaries, sustained after the fraud’s exposure because both governments preferred the fiction to the alternative.

The Europeans, Excluded

One aspect of the 1610 diplomacy is notable chiefly for what it does not contain: any role for the Europeans.

Father João Rodrigues might in an earlier decade have been consulted on a diplomatic initiative of this scale. He was fluent in Japanese, deeply embedded in the Tokugawa court, and had been the architect of the silk-trade arrangements at Nagasaki for more than a decade. But Rodrigues was exiled to Macau in March 1610, the victim of political fallout from the Madre de Deus affair. His replacement as Ieyasu’s foreign adviser, William Adams, was useful for negotiations with the Dutch and English, but he had nothing to offer for an approach to the Ming or the Joseon.

The Jesuits, more broadly, were not consulted. Both branches of the 1610 diplomacy, the Canton message and the Korean track, were entrusted entirely to Japanese agents: the Sō family for Korea, and Gozan Zen monks as foreign secretaries for the Chinese initiative. This was deliberate. Ieyasu had concluded that European intermediation introduced more complications than it solved. The Portuguese were compromised by their religious agenda and their monopoly interests; the Spanish by their colonial pretensions in the Philippines and their tendency to lecture; the Dutch and English were newcomers without the regional expertise required.

The choice carries a particular irony when one recalls that Christian daimyō and Christian soldiers had been, during Hideyoshi’s invasions, among the most active Japanese negotiators with China. Konishi Yukinaga, the baptised Dom Agostinho, had led the diplomatic side of the 1590s negotiations with Ming envoys; his chief emissary Naitō Joan, another baptised Christian, had travelled to Beijing and met Ming court officials face to face. The Jesuit Gregorio de Céspedes had accompanied Konishi’s Christian troops to Korea as their pastor, the first European to set foot on the Korean peninsula. There had been, in other words, a living tradition of Christian-brokered Japanese diplomacy in East Asia.

By 1610, Ieyasu had decided that tradition was over. Japan would negotiate its regional relationships with its own people, through its own intermediaries, in the literary Chinese that served as the region’s diplomatic lingua franca. The Europeans could trade, they could not bring their diplomats.

This was the opening move of what would become, by the late 1630s, the full architecture of sakoku, the system of managed isolation under which Japan would conduct its foreign relations for the next two centuries through four specific “gates”: the Dutch at Nagasaki, the Chinese at Nagasaki, the Koreans through Tsushima, and the Ryukyu Islanders through Satsuma. Two of those four gates were being built in 1610.

Coda

Ieyasu died in 1616, six years after the envoys of 1610 did their work. He did not live to see the missionaries expelled, the Dutch confined to Dejima, or the Portuguese embassy of 1640 turn into a mass execution on the shores of Nagasaki harbour. But he had designed the system that would make all of it possible.

The red-seal ships he authorised in 1604 would carry Japanese silver across Southeast Asia for another three decades. The Tsushima trade would flourish, under the Sō clan’s creative bookkeeping, until the entire Tokugawa order collapsed in the 1860s. The private Chinese merchants whom he had coaxed back into Japanese waters with his Canton message would become, by the late seventeenth century, the largest foreign commercial presence at Nagasaki, confined, eventually, to their own walled compound, the Tōjin yashiki, on the model of the Dutch Dejima and the Korean Waegwan.