As far as I've read, there is no god named 'Herne' mentioned persay.
There is however, a ghost somewhere in england by this name. I'm not too
sure of the story behind it, but I do know it originates somewhere around
1500-1600 a.d. The ghost is believed to look a lot like the way the god
Herne is portrayed in the TV show. i.e. Stag horns and all that. I'll
read a couple of books tonight just to make sure though..