The difficulty of dealing with it at the time at which Herodotus wrote must have been very great. It cannot be said that he has been wholly successful. He has been led, in the process of rejection, to omit details crucially necessary for the understanding of his narrative; he fails, for example, to quote the most notable instance, to account for the absence of the Persian cavalry at Marathon.
He has, again, in the process of adoption, inserted details about the command at Marathon, one of which is a demonstrable anachronism, while others render the exact position of affairs very uncertain.
HERODOTUS’ ACCOUNT OF MARATHON.
But there is a further motive which must be taken into account in a full consideration of the causes which modified his narrative.
H. vi. 121 ff.
To his tale of the campaign is appended a defence of the Alkmæonidæ, which shows that the current Marathonian tradition charged that great Athenian family with having been in collusion with the Mede.
The possible effect of this feature of the tradition on the narrative of an author writing in the days of the greatness of Pericles the Alkmæonid cannot be ignored; though its actual effect, other than these apologetic chapters, is not traceable.
It is, however, evident that the main part of the material for the history of the campaign up to the point where this apology begins, is taken from a version emanating from an “aristocratic” source—that is to say, from that party which was most bitterly opposed to Pericles at the time at which Herodotus wrote.
It has already been pointed out that the Persian expedition of 490 was organized on a less ambitious scale than that of 492, and that it must consequently be concluded that its objects were less ambitious.
How far Herodotus was able in later days to obtain authentic information from the Persian side with regard to the end which Darius had in view, it is impossible to say; but there is a remarkable accord between one of his statements of the Persian motives and his actual narrative of facts. This feature of his account would not be so striking, were it not conspicuously absent from other important parts of his history.