Who tha hell had the stupid idea of casting john wayne as genghis khan?

in the film "the conqueror". it's a terrible movie anyway but lee van cleef was in that film aswell and although i personally never would cast either of them to play a mongolian, lee van cleef would have been a better choice at least looks wise and he doesn't have such a strong accent. anyone here ever seen this crazy idea for a movie before and what are your thoughts?