If you wish accurate interesting historical information on karate history, one of your best sources is the blog maintained by Mario McKenna.
It is a treasure of research over many topics.
Mario is interested in almost all aspects of Karate’s past, and as he researches posts many fascinating details.
Literally you can list your favorite topics and create your own personal book from his posts.
Mario is an accomplished karate-ka in his own right. His background includes studies in many systems, and he is an instructor of Toun’Ryu on of the rarest systems around.
IIn addition to his martial interests, he is also an author who has translated many valuable works which make our knowledge of karate history more complete.