Zoroastrianism is an Iranian religion created by Zoroaster, who lived in eastern ancient Iran around 1000 BC. Other names for Zoroastrianism are Mazdaism and Parsiism. It is the ancestral religion of the Persians.
Zoroastrianism is a monotheistic religion. The Zoroastrian god is called Ahura Mazda. The holy book of Zoroastrianism is the Zend Avesta.