Mazdakism was a Zoroastrian heresy. Mazdak was a Zoroastrian priest who claimed to be a prophet of Ahura Mazda. He attempted to reform the religion with Gnostic elements, and advocated communal possessions and welfare programs. His teachings fell out of favor with the Shahanshah Kavadh I of Persia in 524, but pockets of the heresy survived in some remote areas. There was no religious head of the heresy.