Alexander is said to have burnt the former copy: the latter, stolen by
the Greeks, is reported to have been translated into their language and
to have furnished them with all their scientific knowledge. One of the
Arsacids, Vologesus I., caused a search to be made for all the fragments
which existed either in writing or in the memory of the faithful,* and
this collection, added to in the reign of the Sassanid king, Ardashîr
Bâbagan, by the high priest Tansar, and fixed in its present form under
Sapor I., was recognised as the religious code of the empire in the time
of Sapor II., about the fourth century of the Christian era.*** The text
is composed, as may be seen, of three distinct strata, which are by no
means equally ancient;*** one can, nevertheless, make out from it with
sufficient certainty the principal features of the religion and cult of
Iran, such as they were under the Achæmenids, and perhaps even under the
hegemony of the Medes.

* Tradition speaks simply of a King Valkash, without
specifying which of the four kings named Vologesus is
intended. James Darmesteter has given good reasons for
believing that this Valkash is Vologesus I. (50-75 A.D.),
the contemporary of Nero.

** This is the tradition reproduced in two versions of the
Dinkart.

*** Darmesteter declares that ancient Zoroastrianism is, in
its main lines, the religion of the Median Magi, even though
he assigns the latest possible date to the composition of
the Avesta as now existing, and thinks he can discern in it
Greek, Jewish, and Christian elements.