sentences:  Boyce wrote that the Zoroastrian traditions in the Median city of Ray probably goes back to the 8th century BC.It is suggested that from the 8th century BC, a form of "Mazdaism with common Iranian traditions" existed in Media and the strict reforms of Zarathustra began to spread in western Iran during the reign of the last Median kings in the 6th century BC.It has also been suggested that Mithra is a Median name and Medes may have practised Mithraism and had Mithra as their supreme deity.