Invasion of Ryukyu

• Satsuma han (3000 men in 100 ships) vs. Kingdom of Ryûkyû (Forces unknown)
  • Date: 1609/3-5
  • Location: Ryûkyû Islands

The invasion of Ryûkyû by forces of Satsuma han took place in 1609, and marked the beginning of the Ryûkyû Kingdom's status as a vassal state under Satsuma. The invasion itself involved few casualties, as Ryûkyû had little military strength, and its people were ordered by their king to surrender and to spare themselves any bloodshed.

Ryûkyû would remain a vassal state under Satsuma, alongside its already long-established tributary relationship with China, until it was formally annexed by Japan in 1879 as Okinawa Prefecture.

Background

Satsuma's invasion of Ryûkyû was the climax of a long tradition of relations between the kingdom and the Shimazu clan of Satsuma. The two regions had been engaged in trade for at least several centuries and possibly for far longer than that; in addition, Ryûkyû at times had paid tribute to the Muromachi shogunate (1336-1573) of Japan as it did to China since 1372.

In the final decades of the 16th century, the Shimazu clan, along with Toyotomi Hideyoshi, who ruled Japan from 1582-1598, requested or demanded various types of aid or service from the kingdom on a number of occasions. The repeated refusals of these demands by King Shô Nei (r. 1587-1620), who also ignored outright many communications from the Shimazu and from Hideyoshi, spurred the Shimazu, with the permission of the newly established Tokugawa shogunate (1603-1867), to invade Ryûkyû in 1609, claiming it a punitive mission.

One of the chief events which spurred Satsuma to aggression occurred when Hideyoshi launched the first of two invasions of Korea in 1592. Through messengers from Satsuma, he ordered that Ryûkyû contribute warriors to the invasion efforts, and was refused; he also commanded that Ryûkyû temporarily suspend its official missions to China. The mission traveled to Beijing anyway, on business relating to Shô Nei's formal investiture, and related Hideyoshi's plans to Chinese Court officials there. Shimazu Yoshihisa, lord of Satsuma, then suggested that Ryûkyû be allowed to supply food and other supplies instead of manpower; Hideyoshi agreed, but Shô Nei ignored the related missives.

Following Hideyoshi's death in 1598, and Tokugawa Ieyasu's subsequent rise to power, Shô Nei was asked by Satsuma to formally submit to the new shogunate, a request which was also ignored. The Shimazu then requested to launch a punitive mission against Ryûkyû and, in 1606, were granted permission by the shogunate.

Invasion

The final planning stages for the invasion took place in the second lunar month of Keichô 14 (1609). On the sixth day of that month, the senior Shimazu retainers met and named Kabayama Hisataka to lead the invasion as sôtaishô; Hirata Masamune would serve as his second in command. This marked the beginning of the gathering of forces for the invasion.

On the fourth day of the third month, the Satsuma force, consisting of over 100 ships carrying roughly 3000 warriors, left Yamakawa Harbor for the Ryukyus. The samurai landed at the friendly Kuchinoerabujima the following day, staying there several nights before departing for Amami Ôshima, where the invasion began in earnest on 3/7. The island would not fall to the invaders until 3/16. After an initial landing at Kasari Bay, the invaders moved on to Yamatohama on 3/12, and then to Nishi Yoshimi, securing the island by 3/16.

According to some sources, Ryukyuan resistance fell quickly, but the invading forces simply took their time in an orderly operation. Other sources, however, indicate that 70 of the 75 ships sent to Amami Ôshima were knocked off course by the weather; the force was split, with Hisataka and Masamune landing on different parts of the island. According to these accounts, they were met by roughly 3000 Ryukyuan defenders, hunkered down in wooden fortifications, who were only finally defeated in the end through the use of the arquebus, which would prove a key advantage for the Satsuma force throughout the invasion.

Having secured Amami Ôshima, the invaders moved on to Tokunoshima on 3/20, where significant skirmishes occurred at Shutoku and Kametsu. The invaders met with fierce resistance from locals armed with farming implements, kitchen knives and the like, led by the son-in-law of top royal advisor Tei Dô, and by two unnamed brothers. At least six or seven samurai were killed, along with 200-300 Ryukyuan warriors.

A number of Ryukyuan ships, sent from Okinawa on 3/10, upon word of the attacks on Ôshima, skirted past Tokunoshima on 3/23. The Satsuma forces failed to intercept them. The following day, the samurai seized Okinoerabujima; though the rocky shore looked as though it would prove a landing difficult, in the end the tides carried the Japanese ships over the obstacles, and the island surrendered with little or no fighting.

After these skirmishes on these smaller, more northern islands of the Ryukyu archipelago, the fleet skipped Yorontô and landed at Unten Harbor on the Motobu Peninsula of Okinawa Island on 3/25.

Unten, the chief harbor of the northern parts of the island and one of the only places where the invaders might easily make a landing, is also the site of Nakijin gusuku, formerly the chief castle of the kingdom of Hokuzan; a smaller fortress, called Nago gusuku, lay nearby. The invaders therefore seized first Kourijima, which lies just off the coast from Nakijin, and used this as a base from which to launch their attack. Kourijima fell quickly, and a request for reinforcements was sent to the royal capital of Shuri.

Sources are sadly sparse on the details of the fall of Nakijin. The fortress was commanded by Shô Kokushi, the king's son; Nago Ryôhô, a member of the Sanshikan (the king's top three advisors), led a force of 1000 from Shuri to aid in their defense. Some sources indicate that the samurai reconnaissance force sent on 3/27 discovered the fortress abandoned; others, however, describe a battle on 3/26 in which Nago Ryôhô lost half his force, and note the death of Shô Kokushi on 3/28. Attempts were made on 3/27 to negotiate a settlement with the invaders, but Kabayama Hisataka refused to even meet with the Ryukyuan representatives.

Word of the fall of Nakijin spread quickly, and threw the northern section of the island, known as Kunigami, into chaos and panic. The invaders abandoned Kourijima, seizing Yomitan, a harbor a short distance to the south, which would serve as their base of operations from here on. The force then split, one arm moving south on land, burning villages as it went, while a separate force traveled by sea to Naha, the kingdom's chief port, and a key point of access to Shuri.

Kyan ueekata once again led a team to seek to negotiate with the invaders, and was again refused. On their return to Shuri, bad weather forced them to make port at Makiminato, and to journey the rest of the way to Shuri on foot.

The last fortress before Shuri to fall to the forces advancing on land was Urasoe gusuku. Though sources on the assault itself are scant, Stephen Turnbull surmises that it was done in the same manner as many of the attacks on other gusuku during the invasion; the Okinawan architecture left defenders standing atop the castle walls completely open to enemy fire, a vulnerability of which the samurai arquebusiers took advantage. Sweeps of arquebus fire decimated the defending forces, and then the wooden gates were busted in; at Urasoe, the attackers also burnt down a Buddhist temple, the Ryûfukuji.

The samurai advance next made its way across Tairakyô (today called Tairabashi), an important bridge on the road from Urasoe to Shuri, defeating 100 men who sought to defend it, led by Goeku ueekata. Ryukyuan records of the skirmish indicate that they were felled "in a hail of bullets" and that "[they] did not know about guns like these". Contrary to some myths about the pacifistic nature of the Okinawan people, or their lack of arms, the Ryukyuan defenders were in fact armed with firearms, and their ships and fortresses with cannon, as well, albeit ones based upon Chinese firearms, while the samurai used arquebuses based on European designs.

Meanwhile, the other half of the invading force, which progressed to Naha by sea, were repulsed by the port's defenses, in one of the only Ryukyuan victories of the campaign, though it would prove short-lived. Tei Dô (Jana ueekata) and Tomigusuku Seizoku commanded a force of 3000 soldiers in defending the harbor. Mie and Yarazamori gusuku, located on opposite sides of the harbor, were both armed with cannon. A net or chain of iron was stretched between them, blocking the enemy ships from entering the harbor. The Japanese ships then turned back, making port somewhere nearby to the north, possibly at Makiminato.

Turnbull points out that the maritime attack may have been a feint, to distract from the land-based attack and to draw defenders away from the capital. As Kabayama's diary and other sources do not directly indicate the generals' intentions, it is impossible to know whether the maritime attack on Naha was authentic, or merely a feint. Nevertheless, in the end, the land-based force would succeed in seizing Shuri castle and claiming victory over the kingdom.

The capital desperately tried to organize a defense, but the kingdom's military capabilities were no match for those of the invaders. Ryûkyû's hereditary aristocratic class, unlike that of the Japanese samurai, was not a warrior class, and in any case the kingdom had faced no threats greater than the occasional pirates in nearly two hundred years.

As the invading army bore down on Shuri, another attempt at negotiation was considered but ultimately rejected, as the Ryukyuans realized it was too late. Soldiers lined up at the ornamental Shureimon, the outermost gate of the castle, overlapping their wooden shields in an attempt to produce a defense, but soon fell back to the Kankaimon. The attackers swept defenders off the walls with arquebus fire, as they had done elsewhere, and scaled the walls using ladders.

The invaders entered Shuri Castle on 4/3 and looted it, along with a number of nearby temples and noble residences, stealing or destroying Buddhist scriptures and a variety of other objects of religious or historical significance, along with considerable portions of the royal treasure. They then turned on Naha, entering the city both by land, and through the now undefended harbor.

Shô Nei surrendered on the fifth day of the fourth lunar month of 1609, and was taken hostage, along with his queen, the heir to the throne, and roughly one hundred of his officials. Members of the Sanshikan were sent to the islands to the south, to convey the news of the invasion and to seek their surrender on behalf of the Satsuma forces; by 5/5, the entire kingdom had submitted to Satsuma authority, without any samurai so much as setting foot on many of the islands.

Aftermath

Shô Nei and the other hostages were taken to Sunpu to meet with the retired Shogun Tokugawa Ieyasu, then to Edo for a formal audience with Shogun Tokugawa Hidetada, and then to Kagoshima, where the king was forced to more formally surrender and to declare a number of oaths to the Shimazu clan.

In 1611, two years after the invasion, the king returned to his castle at Shuri.

In the king's absence, Kabayama Hisataka and his deputy Honda Chikamasa governed the islands on behalf of their lord Shimazu Tadatsune. Fourteen samurai officials from Satsuma, along with 163 of their staff, examined the kingdom's political structures and economic productivity, and conducted land surveys of all the islands. Following the king's return to Shuri and the resumption of governance under the royal establishment, three Ryûkyûan officials remained as hostages in Kagoshima until Satsuma was convinced that Shô Nei and his officials were operating in accordance with their oaths. The following year, the lords of Ôzato and Katsuren returned to Okinawa, while the third, Kunjan anji, chose to remain in Kagoshima. He took on a Japanese name and became a samurai retainer to the Shimazu, serving them in battle in the 1615 Osaka Campaign.

Consequences and effects

The surrender documents signed at Kagoshima in 1611 were accompanied by a series of oaths. The king and his councilors were made to swear that "the islands of Riu Kiu have from ancient times been a feudal dependency of Satsuma", and that there was a long-standing tradition of sending tribute and congratulatory missions on the succession of the Satsuma lords, those these were all falsehoods. The oaths also included stipulations that the kingdom admit its wrongdoing in ignoring and rejecting numerous requests for materials and for manpower, that the invasion was justified and deserved, and that the lord of Satsuma was merciful and kind in allowing the king and his officers to return home and to remain in power. Finally, the councilors were forced to swear their allegiance to the Shimazu over their king. Tei Dô refused to sign the oaths and was beheaded.

The kingdom's royal governmental structures remained intact, along with its royal lineage. The Ryukyus remained nominally independent, a "foreign country" (異国, ikoku) to the Japanese, and efforts were made to obscure Satsuma's domination of Ryûkyû from the Chinese Court, in order to ensure the continuation of trade and diplomacy, since China refused to conduct formal relations or trade with Japan at the time. However, though the king retained considerable powers, he was only permitted to operate within a framework of strict guidelines set down by Satsuma, and was required to pay considerable amounts in tribute to Satsuma on a regular basis.

This framework of guidelines was largely set down by a document sometimes called the Fifteen Injunctions (掟十五ヶ条, Okite jûgo-ka-jô), which accompanied the oaths signed in Kagoshima in 1611, and which detailed political and economic restrictions placed upon the kingdom. Prohibitions on foreign trade, diplomacy, and travel outside of that officially permitted by Satsuma were among the chief elements of these injunctions. Ryûkyû's extensive trade relations with China, Southeast Asia, and Korea were turned to Satsuma's interests, and various laws were put into place forbidding interactions between Japanese and Ryûkyûans, travel between the two island nations. Likewise, travel abroad from Ryûkyû in general, and the reception of ships at Ryûkyû's harbors, were heavily restricted with exceptions made only for official trade and diplomatic journeys authorized by Satsuma.

In addition, Amami Ôshima and a number of other northern islands now known as the Satsunan Islands were annexed into Satsuma Domain and removed from the kingdom's territory. These islands remain today part of Kagoshima Prefecture, not Okinawa Prefecture.

References

• Kerr, George. Okinawa: the History of an Island People. (revised ed.) Boston: Tuttle Publishing, 2000.
• Smits, Gregory. Visions of Ryukyu: Identity and Ideology in Early-Modern Thought and Politics. Honolulu: University of Hawai'i Press, 1999.
• Toby, Ronald. State and Diplomacy in Early Modern Japan. Princeton: Princeton University Press, 1984.
• Turnbull, Stephen. The Samurai Take a King: Okinawa 1609. Oxford: Osprey Publishing, 2009.