Like most fantasy writer's I am heavily inspired by Tolkien.
Tolkien actually wrote a bunch of background for Middle Earth and wrote a draft of The Simirilian before he wrote The Hobbit and The Lord of the Rings.
Tolkien had world builder's disease and I kind of do too.
It's a struggle to move from building background material for Scarterra to writing stories for it.
I was inspired by the nonfiction book Guns, Germs and Steel written by Jared Diamond. I tried to use the principles in the book to have cultural advancements (included applied magic) diffuse through Scarterra in a logical fashion.