Stephen Turnbull is a professional advisor and consultant on all aspects of Japanese culture. Thus, he has been a historical advisor on the Uuniversal Pictures film The 47 Ronin, starring Keanu Reeves. However, he is best known for his books on samurai, martial arts, and the military history of East Asia and Europe. He teaches classes on Japanese religion at the University of Leeds and is a visiting professor of Japanese Studies at Akita International University in Japan.