Zoroastrian religion in the Sasanian society also led to the rise of next-of-kin marriage (khevtuk-das). Men were allowed to marry their daughters, sisters, and mother. It was "not merely tolerated, but indeed regarded as acts of piety and great merit, and even efficacious against the demonic forces." The religious leaders of the time promoted marriage within the family, claiming it imitated the creation. Moreover, priests claimed that incestuous marriage "produced stronger males, more virtuous females, and higher quality and quantity of children, and it protected the purity of the race and propagated it." This was met by much resistance, led to more conversions from Zoroastrians to Christianity, and is thought to have led to the downfall of the Zoroastrian religion. There was not as much polygamy in the lower classes as in the wealthy class because men could not afford to support multiple wives.
