Nushin Namazi from Iran writes: "Concerning Zoroastrianism and its acceptance of converts, Jalaledin Ashtiani has written a comprehensive book on Zardosht. He states that it has only been in the 20th century that Zardosht's Gathas, the only remaining documents by him, are linguistically, chronologically, historically and religiously studied, and illuminating points are being found. Prior to that much of what scholars know of the identity of Zardosht was based on traditional and religious narratives.
In his book, he states the following:  "Zarathuthura was born among Aryan tribes where he grew up and carried forth his message, but in his message there is not even the slightest reference to the preference of one tribe or nation over another. It is unlike the Old Testament which claims Judaism was brought for  a single tribe. As a single human being, Zarathustra calls on all the people of the world to join his creed of Truth. His creed carries no profit or gain for any Iranian, race, nation, nationality, monotheist or mazdayansnaist. He is merely an Aryan because he was born in their midst, but in truth he is one of the heralds of truth. As far as his origin is concerned, he is as close to the Aryans of India as he is to the Aryans of Iran"."

Randy Black quotes this: "ZOROASTER c.630 - c.550 BC. Persian Prophet.  Zoroaster, also called Zarathustra, was an ancient Persian prophet who founded the first world religion - Zoroastrianism. According to the Zend Avesta, the sacred book of Zoroastrianism, he was born in Azerbaijan, in northern Persia. He is said to have received a vision from Ahura Mazda, the Wise Lord, who appointed him to preach the truth. Zoroaster began preaching his message of cosmic strife between Ahura Mazda, the God of Light, and Ahriman, the principle of evil. According to the prophet, man had been given the power to choose between good and evil. The end of the world would come when the forces of light would triumph and the saved souls rejoice in its victory. This dualism was part of an evolution towards monotheism in the Middle East. Zoroaster's teaching became the guiding light of Persian civilization. After Alexander the Great conquered Persia, Zoroastrianism began to die out in Persia, but it survived in India where it became the basis of the Parsi religion".

RH: This raises two questions.  That Zoroaster was born in Azerbaijan is "a legend. Modern scholarship does not support this legend".  See P, M. Sykes, History of Persia. The Azeri language is Turkic, whereas the Zend AAvesta is written in Persian. It is commonly  said that the Arabs crushed Zoroastrianism, which however declined after the conquest by Alexander the Great.  The history of that period is very confused, but presumably Alexander brought the Greek religion with him.  An expert on the Persia of that period may  have some comment.

A posting on Zoroaster rejected the tradition that Zoroaster was born in Azerbaijan.and commented "The Azeri language is Turkic, whereas the Zend Avesta is written in Persian."  Cameron Sawyer says: "It's funny; just before reading this, a friend was here in my apartment whose native language is Ancient Persian; he is presently an Austrian citizen but was born in Azerbaijan.  We have three languages in common (English, German, Russian) but we converse in German, which is convenient, since almost no one here knows that language and we can speak without fear of being overheard.
There are enclaves in Azerbaijan where Ancient Persian is spoken to this day.  I have heard it said that the imprint of pre-Islamic Persia is stronger in Azerbaijan than it is in Iran itself.  Some of the finest "Persian" carpets actually come from Azerbaijan.  The name Azerbaijan itself means "Land of Fire" in Persian, and Azerbaijan was a province of Persia for centuries.  Azerbaijan was known as a main center of Zoroastrianism.  I can't say whether or not Zoroaster hailed from those parts or not, but the idea is not absurd on its face".

RH: I hope we can get reliable reports on Iran.  Azerbaijan is divided three ways.  There is the former Soviet republic, which is divided into two parts, and then there is the neighboring Iranian province, itself divided into West (capital Urmia) and East (capital Tabriz). Between the two lies large Lake Urmia. Years ago I saw reports on unrest in the Iranian sector, but since then I have seen no reports on the area, which deserves more attention because of the various claims which might destabilize Iran.  Getting back to Zoroaster, what do Iranian textbooks say about him and his religion? What is the relationship of ancient to modern Persian?  Is it similar to the relationship between Latin and the Romance languages?  Do the Azeris regard themselves as the heirs of the ancient Medes?
Ed Jajko says: ""A posting on Zoroaster rejected the tradition that Zoroaster was born in Azerbaijan.and commented "The Azeri language is Turkic, whereas the Zend Avesta is written in Persian.""  Sorry, but there's no connection.  The Turkish presence in Azerbaijan began in the mid-11th century A.D. and was consolidated over the next two centuries.  If there were any Turks in geographic Azerbaijan when and if Zoroaster was born there -- I have nothing to offer on this -- they were there as traders and craftsmen, and not the massive invasion force of Oguz and Selcuk Turks that displaced the Arabs (who had themselves displaced previous conquerors) and changed the face and the language of that part of the Middle East.

As for the relationship between ancient and modern Persian, it is not like that between Latin and the Romance languages.  It is more like, say, Old English and modern English, if you write the two in mutually incomprehensible scripts, one of which is dead and no longer recognized, required reconstruction by dedicated scholars before the language can be read once again. 

RH: The posting did not speak about Turks in Iran, but said that Azeri is a Turkic language, which is quite different. I was simply repeating what authorities say.