Sources:
http://www.uchinanchu.org/uchinanchu/history_early.htm
http://en.wikipedia.org/wiki/Ryukyu
Personal experience on the island

↓ Transcript
Fact of the Day
On March 11, 1879, the island of Okinawa, home of the 450 year old Ryukyuan kingdom, was annexed by Japan. The Ryukyuan language and culture can still be found on the island, as well as the highest proportion of people over 100 anywhere on Earth.