Satto (察度) (c. 1320 – 1395), also known as Chadu, was a chief of Chūzan, one of three polities formerly on the island of Okinawa. His reign was marked by expansion and development of Chūzan's trade relations with other states, and the beginning of Okinawa's tributary relations with Ming Dynasty China, a relationship that continued for roughly five hundred years, almost until the fall of the Qing Dynasty.
Satto was Governor of the Urasoe district, which surrounded and included Chūzan's capital. On the death of chief Seii in 1350, Satto seized the throne for himself. His own line, or dynasty, however, did not last past his son, Bunei, who was ousted in 1405.
Chinese envoys arrived in Chūzan in 1372, requesting admission of Chinese cultural supremacy and that Okinawa send representatives to Nanjing. Satto complied with these requests without hesitation, as this granted him formal license to trade with the most powerful nation in the region. He sent his younger brother Taiki (泰期) to Nanjing in 1374, as the leader of a mission to formally submit to China, entering into tributary and trade relations. The Hongwu Emperor entertained the Ryukyuan mission, accepted their gifts, and sent them back with various gifts from China, including a royal seal, which served as a symbol of investiture. A Chinese official accompanied the returning mission, and represented the Imperial Court in officially confirming Satto as chief of Okinawa. Though Okinawa was never conquered or annexed by China, this custom of investiture, of formally confirming the chief in the eyes of the Chinese court, continued as part of tributary relations until the dismantling of the Ryūkyū Kingdom five centuries later. There were at least nine tributary missions to China over the next twenty years, three of them led by Taiki.
Diplomatic and trade relations were also established with a number of other states during Satto's reign, including the kingdoms of Korea and the Ayutthaya Kingdom of Thailand. Trade was conducted with these kingdoms, and with China and Japan, via a number of small islands that served as way-stations. Tanegashima, for example, was used as a transfer and supply point for traders bound for Japan's main islands and the Inland Sea. Miyakojima and the Yaeyama Islands, small islands to the south of Okinawa in the Ryukyu island chain, were among those that sent tribute to Chūzan.
Satto also established the Chinese immigrant community of Kumemura in 1392, a short distance from the capital at Shuri. These Chinese would, over the ensuing decades and centuries, intermarry with the local Ryukyuans; Kumemura grew into a center of Chinese studies, and its Chinese inhabitants and their descendants served the kingdom as diplomats, interpreters, and related roles.
Another important development introduced by Satto was the creation of the post of Ō-shō (王相), or King's Assistant. Though direct monarchical rule remained important and powerful in Okinawa for at least a few generations, this marked the beginnings of a bureaucracy that gradually replaced the chief's direct rule, drafting and implementing policy in his name.
Satto died in 1395, and was succeeded by his son Bunei. Missions sent to Nanjing announced the chief's death, and formally requested investiture for his successor. The "Mirror of Chūzan," a history of Ryukyu written by Shō Shōken in the 1650s, cites Satto's death as an example of tentō (天道), a concept closely related to the Confucian Mandate of Heaven. Though he describes Satto as a good chief overall, Shō accuses him of giving in to luxurious temptations and of losing the proper degree of humility; thus, Shō explains, Satto was guided by tentō to touch a venomous snake in his sleep and to be killed.
- Suganuma, Unryu. (2000). Sovereign Rights and Territorial Space in Sino-Japanese Relations, p. 46. at Google Books
- George H. Kerr. (2000). Okinawa: The History of an Island People, p. 52 , p. 52, at Google Books; although the paramount leaders of Okinawa beginning with Shunten (c. 1166 – c. 1237) are commonly identified as "kings," Kerr observes that "it is misleading to attribute full-fledged 'kingship' to an Okinawan chief in these early centuries... distinctly individual leadership exercised through force of personality or preeminent skill in arms or political shrewdness was only slowly replaced by formal institutions of government — laws and ceremonies — supported and strengthened by a developing respect for the royal office."
- Kerr, George. (2000). Okinawa: The History of an Island People, p. 62., p. 62, at Google Books
- Shimaziri District Elementary School Social Studies Research (島尻地区小学校社会科研究会 Shimajiri Chiku Shōgakkō Shakaika Kenkyūkai?) (2002). Okinawa History Biographical Dictionary (沖縄歴史人名事典 Okinawa rekishi jinmei jiten?), p. 85.
- Relations are believed to have been first established with Goryeo in 1389, which fell three years later and was replaced by Joseon, though relations were for the most part undisrupted.
- This represents the Okinawan language reading of the characters; the same term is read as tendō in Japanese language, and as tian-dao in Chinese pinyin.
- Kerr, George H. (1965). Okinawa, the History of an Island People. Rutland, Vermont: C.E. Tuttle Co. OCLC 39242121
- Smits, Gregory. (1999). Visions of Ryukyu: Identity and Ideology in Early-Modern Thought and Politics, Honolulu: University of Hawaii Press. ISBN 978-0-824-82037-4; OCLC 39633631
- Shimaziri District Elementary School Social Studies Research (島尻地区小学校社会科研究会 Shimajiri Chiku Shōgakkō Shakaika Kenkyūkai?) (2002). Okinawa History Biographical Dictionary (沖縄歴史人名事典 Okinawa rekishi jinmei jiten?). Naha: Okinawa Bunka-sha. OCLC 170411659 (1997 ed.)
- Suganuma, Unryu. (2000). Sovereign Rights and Territorial Space in Sino-Japanese Relations: Irredentism and the Diaoyu/Senkaku Islands. Honolulu: University of Hawaii Press. ISBN 9780824821593; ISBN 9780824824938; OCLC 170955369
|Chief of Chūzan