One of the world’s oldest monotheistic religions. It once was the official religion of Sassanid Persia and played an important role in Achaemenid times.
According to internal and external histories, a prophet named Zártosht (Zoroaster) lived in Iran / Persia no earlier than 1700 BC and no later than 600 BC. He came to reform ancient Aryan / Indo-Iranian religious practices (some of which were parallel to those of ancient India). Zoroastrianism is called Mazdayasni by the Parsis and other followers of the faith, after the name for God, Ahura Mazda meaning “All Knowing Entity”.
The Holy Book of Zoroastrianism is called the Zend Avesta. The Zend is the commentary on the teaching and the Avesta is the original teaching in the Holy book. Before the invasion of Alexander and the Muslim Conquest there was a total of 21 Books followed by Zoroastrians called Nasks. Only one of these Nasks remains complete, called the Vendidad. The traditional explanation for the loss of most of the Nasks is that Alexander’s regime persecuted the faith and destroyed its texts. This explanation is questioned by some historians. The 21 Nasks did not only contain religious literature but also included works on Medicine, Astronomy, Botany and Philosophy.
Only a portion of the Avesta, known as the Gathas (The Hymns) are attributed to the Prophet Zoroaster himself. The Yashts are smaller books for Prayer, Other books included are the Afringan, Nyayish, Gah, Sirozah which partially contain some scriptures of the lost 14th and 21st Nasks (Lost books). Other teachings are the Yasna which means Sacrifice and contains prayers for sacrificial rituals; the Visperad is a collection of doctrines that are used for exorcism and religious law. The Visperad also includes cosmological, historical and eschatological material.