 The movie is based on a play by Alan Bennett (I) (qv) called "The  Madness of George III". The popular story in the UK is that the  movies title is different from that of the play because it was  thought the American audience might mistake it for a sequel. While  not wholly true, director Nicholas Hytner (qv) has confirmed that  it was "not wholly untrue" and it is now widely held that this  almost certainly did play a part in the titling of the film. In the  UK it would be obvious to anyone that "George III" referred to King  George III, but it was felt that elsewhere this might not be so  clear and that adding "King" to the title might help. While this  explains part of the title change, it glosses over the dropping of  the "III", adding renewed weight to the original theory.