Hard to Be a God

The original novel was published in 1964.

The novel follows Anton, an undercover operative from the future planet Earth, in his mission on an alien planet, that is populated by human beings, whose society has not advanced beyond the Middle Ages. The novel's core idea is that human progress throughout the centuries is often cruel and bloody, and that religion and blind faith can be an effective tool of oppression, working to destroy the emerging scientific disciplines and enlightenment.