Stretching for 1300 kilometers, Ryukyu once was a kingdom embracing the Amami Islands south of Kyushu, Japan, all the way further south to Hateruma and Yonaguni Islands, the latter situated east of Taiwan. Ryukyu's major island was what we today call Okinawa main island, the largest of more than 160 islands. Okinawa is also the name of the second largest city on the main island and the name of Japan's southernmost prefecture.