Immortals of Meluha

The story of The Immortals of Meluha is set in 1900BC and operates on the premise that Shiva was a mortal, a simple man whom legend turned into God.
Amish summarises his fundamental premises as:
"I believe that the Hindu gods were not mythical beings or a figment of a rich imagination.
I believe that they were creatures of flesh and blood, like you and me.
I believe that they achieved godhood through their karma, their deeds.
With these premises, an interesting read is assured."

While parts of the story are rooted in mythology and some parts are corraborated by history - like the description of town planning by the Meluhans - most parts are pure speculative fiction.