It is impossible to fix exactly the era when the great reformer Zarathustra--"splendor of gold"--lived. The Greek and Roman historians make him very ancient. Xanthos of Lydia, 470 B. C., the first Greek writer who mentions Zoroaster, is convinced that he must have flourished about six hundred years before the Trojan war. Aristotle and Eudoxus place his era even earlier. Berosus, the Chaldean priest and historian, who translated the history of his native country, Babylonia, into the Greek language, and dedicated the work to Antiochus, one of the Greek kings of Syria, makes him a king, or rather founder of a dynasty which reigned over Babylon between 2200 and 2000 B. C.[16] The Fire-worshippers hold that their great priest and reformer lived about five hundred and fifty years B. C. They identify him with the great Kavan-Vistaspa of the Zend-Avesta, called Khai Gustasp in the _Shahnamah_.[17] But it is very evident that even the ancient Persians themselves were very uncertain as to who this Kavan Vistaspa was. It is clear, however, that Darius's father, who was also named Vistaspa, and the Kavan-Vistaspa of the Zend-Avesta and the _Shahnamah_, were entirely distinct persons. There is very little doubt that this confusion of opinions is owing to the similarity of names. A very common habit even in India to-day is to name persons after heroic kings, great priests, or even after the gods, without any mark being added to distinguish them in after years; and when any period of time has elapsed it is almost impossible to separate the personality of the father from the son, or the disciple from the teacher, or the priest from the god. Zoroaster, or rather "Zara Thustra," means illustrious like gold, or, in another sense, simply high priest; and this being taken afterward as the proper name of the celebrated priest and reformer of ancient Iran, gave rise to the endless confusion of dates and opinions which has always prevailed with regard to the age in which he lived. There is, however, internal evidence in the language and religion which he reformed that he lived at a very early age, and there are many traces of his great antiquity in the Zend-Avesta itself. First, that he stands at the head of the extensive Zend literature,[18] which must have required centuries for its growth, and which was already in a state of perfection when Buddha, the founder of Buddhism, was born, from four to five hundred years before Christ; and secondly, that he is expressly called Aryana Veèdgo, "the celebrated one," in the Aryan home whence the Aryans, now called Hindoos, emigrated in times immemorial. This title, Martin Haug justly observes, would not have been given him had his followers not believed him living at that early time. Under no circumstance can we assign to him a later date than the year 1000 B. C.