Jim Henson set the stage for it all.
Those that could labor through the Lord of the Rings read, they could enjoy its rich back drop. Yet it was Jim brought a full bloom story to color and life. The Dark Crystal movie that set the tone for alot of things; Lord of the Rings, Harry Potter, Avatar, Willow, etc
The man had back story for the grass and the bugs in the grass in this movie!
A guiding light in writing for scripts of fantasy, for sure.