On Rex Harrison Playing the Role of King Mongkut In the 1946 Movie, "Anna and the King of Siam"

Well, I guess that if John Wayne can portray Genghis Kahn on the silver screen, a stuffy British actor can take a whack at this role (plus there weren't exactly a plethora of thespians in old Tinseltown, particularly after WW 2). It only makes sense, right?