Just read a new book entitled Itosu Anko by Joe Swift. If you are interested in the evolution of Karate in the late 1800's to early 1900's and how our art came to be, this is the source. Highly researched and translated by Swift Sensei, it explores the influence of China, Japan, and original Okinawan fighting arts on modern Okinawan karate, using first and second hand accounts of the masters, themselves, as well as supporting articles from Okinawan newspapers from that time. The book revolves around Itosu, his teachers and his students to convey the real story. It is not a rehash of other works as Swift Sensei spent twenty years or more living there and earning the trust of the older masters still living. He is fluent in Japanese and had access to sources others have not. It sort of picks up where Patrick McCarthy's Bubishi leaves off. It's not cheap, but there is nothing else like it out there.