I have no idea what the proper title for this movie is. My DVD has SAMURAI PIRATE printed on it, but the movie itself says THE GREAT BANDIT. But then IMBb and the poster above say THE LOST WORLD OF SINBAD which makes no sense because nobody in the movie was called Sinbad and there wasn't any lost world. I'm going to go what it has onscreen.
Most people only know Toshiro Mifune from his 16 Kurosawa films, but he also made a metric shitload of other movies including this one in which he's a pirate who at the beginning of the movie has his ship destroyed by a storm. He (and his treasure chest) are floating along on a big piece of wood when he's overtaken by the dreaded Black Pirate. The pirates steal his booty and leave him adrift. He wakes up many days later on a beach. A hermit with magical powers has been taking care of him. Toshiro goes to the nearest town where he sees a beautiful princess and learns that the kingdom has been taken over by some asshole. He decides that ain't cool, so he sets off to the castle to get to the bottom of this shit.
There's lots of interesting moments (evil witch turning people into stone, good wizard dude turning himself into a fly so he can spy, Toshiro flying around on a giant hang glider), but over all it got pretty boring pretty quick. Personally I have no desire to ever see it again and I was actually disappointed in it. I guess I was expecting something more along the lines of the "Sinbad" movies from the 50's and 70's.
Worth watching, I guess, if you're a huge Mifune fan but don't expect to be impressed.