In the III century AD, during the Sassanian dynasty, a prophet by the name of Mani preached a new, syncretic doctrine in Iran, influenced by Zoroastrianism, Christianity and Buddhism. Born around AD 216, Mani was brought up in a Gnostic Baptist sect in Babylonia. At the age of 24, a few years after having received his first revelation from God, he left the community and set off on a long journey through Iran as far as the Indus Valley. On his return, King Shapur I invited him to court to expound his doctrine, and gave him permission to preach throughout the empire. But Manichaeism suffered badly from the religious persecutions of the period directed by the high priest Kartir. In 274 or 276, during the reign of Bahrain I, Mani was imprisoned and executed.
The belief in the two opposite principles of Light and Darkness appears once more in connection with Manichaeism. Here again, events unfold over three periods; in the first one, the two principles are separate, each in its own kingdom, until Darkness invades the world of Light. Then begins the middle period, that of the mingling of the principles. Primordial Man, an emanation of God, is defeated by the demons who take away his armour (Light). The particles of Light thus captured are mixed with Darkness and Matter. While some particles are recovered by the Living Spirit to create the Moon, the Sun and the Stars, the more defiled ones remain captive. At this point, the Archons, demons bound by the Living Spirit and who beget the plants and the animals in which the particles of Light are incorporated, intervene. The human species was created by Concupiscence in the hope that as he multiplied, Man would scatter the particles and prevent their return to their own kingdom. To frustrate this plan, the Saviour communicates to the First Man, Adam, the Gnosis, or total knowledge about his origin and his vocation: although his body was engendered by demons, his soul is capable of freeing itself and returning to the Light. In the last period, when all the particles have returned, Light and Darkness will once again be separated and the demons and the damned enclosed for eternity in the world of Obscurity.
The death of Mani and subsequent religious persecution led to an exodus of Manichaeans to the ends of the Sassanian Empire. Many fled to Egypt, and even to Chinese Turkestan, where their faith survived at least until the XIII century. In the Chinese south-eastern province of Fujian, Manichaean communities flourished even till the late XVI century. But in Muslim as well as in Christian territory, the Manichaeans were considered heretics and a political threat. The persecutions continued and, at the beginning of the X century, the Manichaean Church left its native region for Central Asia.