Manichaeism is an ancient religion founded by Mani, who was born in Persia and died circa A.D. 276. Its believers claim to be Christians, but other Christian groups reject their beliefs as heretical. Manichaeism has often been associated with Gnosticism, another early form of Christianity that has also been rejected as heretical by most Christians.
Mani was brought up as a Mandaean,and he claimed to be a prophet sent to complete the message of Moses, Zoroaster, Jesus and the Buddha. After Mani's death, Manichaeism spread to both the east and the west. It became popular in the Roman Empire, and for a while it was a major competitor to what is now accepted Christianity. Augustine of Hippo, for instance, was a Manichee for several years before switching to Catholicism. In the east, Manichaeism spread as far as western China.
The main principle of Manichaen theology is dualism, the belief that the universe is run by two gods, one good and the other evil, these two gods of of equal power and in a constant battle for supremacy.
After some early successes Manichaeism then entered a decline. It is now mainly practised by obsucre and persecuted groups in southern Iraq and has no more than a few thousand followers at most.
Compare with: Zoroastrianism