According to the 'Zend Avesta', the sacred book of Zoroastrianism, he was born in Azerbaijan, in northern Persia, probably in the seventh century BC, although some scholars put the time-frame for Zoroaster much earlier.

He is said to have received a vision from Ahura Mazda, the Wise Lord, who appointed him to preach the truth. Zoroaster began preaching his message of cosmic strife between Ahura Mazda, the God of Light, and Ahriman, the principle of evil. According to the prophet, man had been given the power to choose between good and evil. The end of the world would come when the forces of light would triumph and the saved souls rejoice in its victory.

This dualism was part of an evolution towards monotheism in the Middle East. Zoroaster's teaching became the guiding light of Persian civilization.

After Alexander the Great conquered Persia Zoroastrianism began to die out in Persia, but it survived in India where it became the basis of the Parsi religion.

Life and Work of Zoroaster