Samurai I: Musashi Miyamoto is the first film in the Samurai trilogy, directed by Hiroshi Inagaki and starring the great Toshiro Mifune. This is #14 in the Criterion film collection. It won best foreign film in the 1955 Academy Awards. This is an action-filled character study. Excellent story based on a historical figure.
Rotten Tomatoes doesn't have a critics score, but the audience score is 84%. TCM has an overview.