The traditional histories of the Ryukyu Kingdom claim the island of Okinawa split into three kingdoms under the reign of the legendary king
Tamagusuku. Northern Okinawa was said to have become the lordship of
Hokuzan, while southern Okinawa became the lordship of
Sannan. Tamagusuku controlled the region of
Chūzan in central Okinawa around the communities of
Urasoe,
Shuri, and
Naha, owing the allegiance of a number of local lords and chieftains known as . Whether these three polities existed as territorial states is debated academically. Tamagusuku was said to have died in 1336, and left the kingdom to his ten-year-old son
Seii. His mother served as his regent.
Reign , seen here as a modern reconstruction. According to the official histories, Satto was born to a peasant family in Jana, a village near Urasoe. He was wise and hard-working, and was able to purchase large amounts of iron tools from Japanese merchants with help from his wife. He distributed these tools among the peasants, bringing him acclaim and allowing agriculture to flourish in the region. Satto rose to prominence and took control of Urasoe, the capital of Chūzan, around the time of Tamagusuku's death. Seii died around 1355, and local rulers refused to enthrone the young king's heir. Satto took control of the kingdom, ruling from the of
Urasoe, purportedly with a large amount of popular support. Although later histories describe the as the capital of the legendary king
Shunten and the proto-historical
Eiso, Satto is likely the earliest known king to rule from the site. Remains from the site date to around the late 14th century, and the appears to have become a significant power base around 1350. "Satto" may be a generic title for a ruler; a king of Sannan bears the name
Shōsatto, and a Ryukyuan diplomat sent by Satto to China in 1392 is also named Satto in the Ming annals. It is likely based off the Korean word , a local official, and there may have been multiple rulers who ruled under the name. Due to this, historian
Gregory Smits theorizes that Satto may have been a seafaring merchant from
Goryeo who fled to Okinawa around the 1330s. Smits suspects a relation with
Onsadō, a king of Sannan mentioned in the
Joseon annals who fled to Korea in 1398. Many historians believe Onsadō was the same person as Shōsatto. The ('Mirror of Chūzan'), a 17th century official history of the Ryukyu Kingdom, described Satto as a good king who in his later reign fell into decadence and lost his humility. He is credited with establishing
Gokoku-ji, the second Buddhist temple in Okinawa, in 1384. The earliest portions of
Shuri Castle may have been constructed under his reign, and he purportedly transferred the capital to Shuri. He is credited with establishing the community of
Kumemura, a Chinese merchant enclave adjacent to Shuri, in 1392.
Tribute and international relations The
Ming dynasty took over China from the previous
Yuan in 1368, and began to establish its
tributary system across East Asia. A Ming official named
Yang Zai traveled to Okinawa after an unsuccessful mission to
Kyushu, and likely explained the Chinese tributary system to Satto before returning home to China. He returned to Chūzan in 1372 with a decree from the Ming court asking for tribute. Satto accepted, and was given the title "King of Ryukyu", despite only controlling a small region of central Okinawa. Accepting tributary status allowed for lucrative trade licenses with China. Two years later, Satto dispatched his brother Taiki to Nanjing alongside a group of emissaries and an offering of Okinawan goods. The
Hongwu Emperor gave the Chūzan emissaries various gifts, and sent a court official to accompany them home. Satto was given textiles, ceramics, books, alongside a silver
royal seal and documents officially recognizing him as king. In 1382, the Ming began to recognize two other polities in Okinawa, Hokuzan and Nanzan, as kingdoms. All three states sent frequent tributary missions, although Hokuzan and Nanzan were forced to conduct trade through Chūzan's port of Naha. Between 1372 and 1398, 57 tributary missions were sent from Okinawa, the most sent to China by any country. Satto is the first ruler of Okinawa mentioned in Chinese records. Historian Ikuta Shigeru theorizes from inconsistencies in tribute records that Satto, his supposed prince
Bunei, and the Sannan king Shōsatto, may have been siblings. In 1389, the year after
Taejo of Joseon took control of Korea from Goryeo, Satto dispatched a embassy to the
Joseon court. The envoy brought a group of Koreans who had been captured by pirates, alongside various gifts from Okinawa and the surrounding regions. In 1394, Satto petitioned Joseon court to send Shōsatto, the son of the king of Sannan, back to Okinawa. Legends describe
Yonahasedo Toyomiya, a member of one of the feuding noble clans in the
Miyako Islands, sailing to Okinawa as part of a group of Miyako students and studying in Chūzan for three years of Satto's reign. Toyomiya pledged tribute to Chūzan and received gifts and trade agreements from Satto, after which he returned south, purportedly becoming the lord of Miyako and
Yaeyama. ==Death and legacy==