The document summarizes the history of Okinawa Island and the Battle of Okinawa that took place from April to June 1945. Okinawa was originally a prosperous trading kingdom due to its location along trade routes between Japan and China. It was later invaded by Japanese samurai in 1609. The Battle of Okinawa in 1945 was one of the largest battles of World War II and resulted in over 100,000 Japanese and Okinawan civilian casualties as well as significant Allied and Japanese military losses. It marked one of the bloodiest battles of the Pacific War.