Stories of Gods and Heroes by Thomas Bulfinch

Zoroaster

Our knowledge of the religion of the ancient Persians is principally derived from the Zendavesta, or sacred books of that people. Zoroaster was the founder of their religion, or rather the reformer of the religion which preceded him. The time when he lived is doubtful, but it is certain that his system became the dominant religion of Western Asia from the time of Cyrus (550 BC) to the conquest of Persia by Alexander the Great. Under the Macedonian monarchy the doctrines of Zoroaster appear to have been considerably corrupted by the introduction of foreign opinions, but they afterwards recovered their ascendency.