Title?

We all know (or pretend to know) that the original Japanese title for this film means "Cobweb Castle" (or some variation thereof). But this film is known to us Anglophones as "Throne of Blood" (a very good title, I might add). How did this movie come to have the English title "Throne of Blood"? Why isn't the motion picture known by some other name? (This is not a quiz -- but a sincere question.)