1.101), Herodotus speaks of the magi as one of the tribes/peoples (ethnous) of the Medes. In another sense (1.132), Herodotus uses the term "magi" to generically refer to a "sacerdotal caste", but "whose ethnic origin is never again so much as mentioned." According to Robert Charles Zaehner, in other accounts :

"We hear of Magi not only in Persia, Parthia, Bactria, Chorasmia, Aria, Media, and among the Sakas, but also in non-Iranian lands like Arabia, Ethiopia, and Egypt. Their influence was also widespread throughout Asia Minor. It is, therefore, quite likely that the sacerdotal caste of the Magi was distinct from the Median tribe of the same name."