There is a good episode of the BBC podcast "In Our Time" on the history and philosophy of Zoroastrianism: "How was the religion established in Ancient Persia,

There is a good episode of the BBC podcast "In Our Time" on the history and philosophy of Zoroastrianism: "How was the religion established in Ancient Persia, what is its body of beliefs and how have they been developed and disseminated? With Vesta Sarkhosh Curtis, Curator of Ancient Iranian Coins in the Department of Coins and Medals at the British Museum; Farrokh Vajifdar, Fellow of the Royal Asiatic Society; Alan Williams, Senior Lecturer in Comparative Religion at the University of Manchester." https://www.bbc.co.uk/programmes/p005bc5v https://www.bbc.co.uk/programmes/p005bc5v