Ryukyu Kingdom was an independent kingdom which ruled the Ryukyu Islands from the 14th century to the 19th century. The King of Ryukyu unified Okinawa Island and extended its rule over the Amami Islands in modern Kagoshima Prefecture and the Yaeyama Islands near to Taiwan. Diplomatically the kingdom established tributary relations with China, during its Ming and Qing Dynasties, and developed trade relations with Japan, Korea and many Southeast Asian countries, including Siam, Pattani, Malacca, Champa, Hue, and Java. In 1609, the kingdom fell to an expeditionary force from Kagoshima. As Ming China prohibited trade with Japanese, the Lord of Satsuma utilized the kingdom as a puppet state for profitable trade with China. The King of Ryukyu also sent diplomatic missions to Edo, capital of feudal Japan. The modern Japanese government abolished the kingdom and established the prefecture of Okinawa in 1879. Qing China made some diplomatic protests to the Japanese government in vain.
Major events 1372 The first Ming envoy visited Okinawa which was divided into Three Mountains (principalities). The beginning of the formal tributary relations with the Chinese Empire. 1416 The Middle Mountain (Chuzan) occupied Nakijin Gusuku, capital of the Northern Mountain (Hokuzan). 1429 The Middle Mountain occupied Shimajiri Osato Gusuku, capital of the Southern Mountain (Nanzan), unifying Okinawa Island. The Kingdom of Ryukyu was established with the capital at Shuri Castle. 1477 The third king, Sho Shin, ascended the throne. Golden age of the kingdom. 1609 Lord of Satsuma in Southern Kyushu conquered the kingdom. King of Ryukyu paid homage to him. 1624 Lord of Satsuma annexed the Amami Islands. 1853 Commodore Matthew Perry of the US Navy visited the kingdom. 1866 The last official mission from the Qing Empire visited the kingdom. 1872 Japan put the Ryukyu han. 1874 The last tributary envoy to China was dispatched from Port Naha. 1879 Japan replaced the Ryukyu han with Okinawa Prefecture. The last king of Ryukyu was transported to Tokyo .
History of Okinawa (http://members.tripod.com/~MickMc/history.html)