Answer:
The term 'mythology' comes from the Greek mythos (story-of-the-people) and logos (word or speech), meaning the spoken story of a people. Every civilization of the ancient world developed a belief system, which is characterized as 'mythology' in the present day but which, for them, was religious belief, and this was as true for ancient Persia as for any other. These systems only became designated as “mythological” after they had been replaced by others which, even so, continued to express the same values emphasizing the forces of good and order over those of evil and chaos.
Oral tradition was especially important and storytelling a central value in ancient Persian culture, and so the stories of the old continued to be told, and many of the deities, now reimagined, appear in the works of the oldest monotheistic religion, Zoroastrianism, which developed between c. 1500-1000 BCE. This faith developed from an earlier polytheistic system featuring a pantheon of gods, led by their king Ahura Mazda, who stood against the forces of the evil spirit Angra Mainyu. The prophet Zoroaster revised this earlier vision so that Ahura Mazda became the one true god while the most significant of the other deities became emanations and manifestations of his eternal goodness.
The stories which had once made up the religious understanding of the people now became fables – myths – which entertained while also encouraging the same cultural values they always had, only now in a monotheistic context. The god Mithra might still be invoked and his battle with the dragon Azhi Dahaka still be told, but it was understood that Mithra was now simply Ahura Mazda fighting the forces of evil.
Many of the other gods of the original Early Iranian Religion were forgotten, however, and are only known through brief reference in Zoroastrian scripture, religious literature, and the tales collected and written down in works such as the Shahnameh and One Thousand Nights and a Night. Since ancient Iran/Persia maintained an oral tradition until the Sassanian Period (224-651 CE), there is no ancient text along the lines of Hesiod’s Theogony or Homer’s Iliad and Odyssey (both c. 8th century BCE) describing and defining the old gods at the time they were being worshipped. Inscriptions found in the ruins of cities like Susa or at the great temple of Chogha Zanbil (also known as Dur Untush) provide only the most basic allusions to deities predating the development of Zoroastrianism.
The gods, creatures, and heroes who made up these early stories of ancient Persian mythology are therefore scattered amongst the various works of Zoroastrianism and later collections of myth and fable. A comprehensive list, or at least an attempt at one, should therefore prove useful to anyone interested in the subject of Persian mythology and religion specifically or the study of myth, folklore, and religion generally.
The following is a list of the various entities of pre-Zoroastrian Persia who appear in some of the most famous myths and legends. The list attempts to be complete but will omit some minor deities and even some heroes whose qualities are represented by others more famous. The list will also include religious concepts and places considered important in ancient Persian religion, such as the Chinvat Bridge which souls crossed from life to death or the House of Song, the Persian vision of paradise. The following are all drawn from the sources listed below in the bibliography.
Explanation: