The Ryukyu Kingdom is a country that no longer exists in present-day Okinawa. Before Japan took control of it during the Meiji Era, it was an independent country with its own culture, government, and language. Okinawa was a major trading center in Asia, so there are aspects of Chinese, Japanese, and other Asian cultures that were blended into the native Okinawan culture.
The name Ryukyu is a transcription of the Chinese name for the region, Liuqiu (written as 琉球 in Chinese characters).
Before the Ryukyu Kingdom was created, Okinawa was made up of three countries: Nanzan, Chuzan, and Hokuzan. Chuzan took over the other two kingdoms, united the three kingdoms, and created the Ryukyu Kingdom. The kingdom had its own dynasty of kings and they ruled from Shuri Castle in the city of Shuri. Although they used to be different cities, Shuri is now in the northern part of present-day Naha.