At the date of Darius, 521 B. C., Zoroastrianism was the national religion of the Persians. In one of the inscriptions of Darius, we find this reference: “Mazda, who created this earth and that heaven, who created man and man’s dwelling place, who made Darius king, the one and only king of many.” This and other references in the inscriptions indicate the time of Zoroaster as before the date of Darius. Ancient Persian traditions represent Zoroaster as a native of Bactria, and that the important address to king Vistacpi and his court was delivered in the ancient city of Balkh. Dr. Bunsen says of Zoroaster’s conception, that “it was not less grand than that of Abraham; but that the distinctive difference lay in these facts; Zoroaster attempted a conciliatory compromise between his stern antagonism to nature worship, and the retention of the ancient rites and symbols of such worship.” Abraham, on the other hand, excinded nature worship altogether, and sought to banish it as utterly as possible from his religiously segregated society. “In this,” he urges, “the Hebrew man of God stands above the Aryan.” From happy Bactria, this religion of “excellence” spread among the numerous tribes of Iranians into all Persia, finally becoming the state religion. This was also known from its earliest to its latest history, as the “Book Religion.” According to Parsee tradition, Zoroaster was the author of the Avesta, which, when first written, consisted of twenty-one nosks or parts. It is also stated that this book was in a form of writing invented by Zoroaster, and which the Maga, or priests of this cult called the “writing of religion.” It was written on twelve thousand cow-hides, in ink of gold and the work was bound together by golden bands. Various Greek writers, who followed the wake of Alexander’s conquests in Persia, claim to have seen the original, which was preserved in the archives of Persepolis. Traditional accounts state that there were two copies of this work, one of which was destroyed in the palace of Persepolis, which was burned by order of Alexander, and the other was destroyed by the Greeks in some other way. There were also copies of the various nosks or parts in the hands of the priesthood, which thus escaped destruction. After the death of Alexander, the Zoroastrian priests gathered the remaining fragments, putting these into book form. Five hundred years later, at the close of the Parthian dynasty in Persia, another collection of the Avesta fragments, both oral and written, was instituted, at the command and under the patronage of King Vologases, the last of the Arascids, about A. D. 225. The work of editing and revising these collections was continued under the early Sassanian kings, with whom the ancient nationality again became ascendant, and with this, the ancient Persian religion and its literature. The new Avesta thus produced was proclaimed canonical.