He then enters upon the description of that affair at Naxos which immediately preceded the Ionian revolt.
The story of these operations in Thrace which are subsequent to and the direct outcome of the so-called Scythian expedition, is one of the most obscure chapters in Herodotus’ history. He had manifestly the greatest difficulty in obtaining information with regard to the events of the time. That which he did get he got from various sources, whose discrepancies he only partially succeeded in reconciling.
The modern writer is obliged to face the historical situation with the courage alike of necessity and despair; of necessity, inasmuch as the history of these years is of the utmost importance in the story of the Persian relations with Europe, and, consequently, with Greece; of despair, in that he must feel that detailed criticism of such material must border on mere eclecticism. On the main outlines the question it is, however, possible to arrive at conclusions which have some sound foundation in evidence.
It seems quite clear that these campaigns of Megabazos and Otanes aimed at the reduction of the Thracian races in Europe. In ordering them Darius was probably pursuing the policy which had underlain the so-called Scythian expedition. His stay at Sardes, for what cannot have been less than the better part of a year after his return from that expedition, indicates certainly that he considered that the affairs of the westernmost extremity of his empire demanded his personal attention more imperatively than affairs elsewhere, and may well imply that they were of a nature to cause him some anxiety. There had certainly been some disaster in the Scythian expedition. It had been followed by the revolt, not merely of the towns on the European side of the Propontis, but of places like Antandros in the Troad, which Otanes had subsequently to reduce.
The strategic policy observed in the campaign of Megabazos is striking in that the revolted cities are practically ignored. Its results are in many respects uncertain. Herodotus describes them in a descending scale;—first, as having consisted of the subjugation of all the Thracians; secondly, as being confined to the conquest of the coast regions; thirdly, as leaving even the conquest of these regions incomplete in the neighbourhood of Mount Pangæus. DESIGNS OF DARIUS IN EUROPE. It has been pointed out that the first two statements may be reconciled as implying subjugation in two different degrees; but the third constitutes, in whatever way it be regarded, a significant exception.
As far as the revolted cities are concerned, it is possible that Darius thought he could bide his time for dealing with them, and that the larger Thracian policy first demanded his attention. The cities were not powerful enough to do any active damage meanwhile.
How far was Megabazos successful in carrying out this larger policy? If any conclusion is to be drawn from the fact that Darius before leaving Sardes put Otanes in command in place of him, it is that the king was not satisfied with what he had achieved. Nevertheless, the success of his operations seems to have been sufficient to convince the Macedonian king Amyntas of the advisability of submitting to Persian suzerainty. What Megabazos certainly did was to open up the coast road to the West; and this, if the tale of the Pæonians is to be regarded as significant, he seems to have done by the express orders of the king. In any case the advance along this line is certainly a significant fact.
The objects, then, of Megabazos’ campaign appear to have been—
(1) To complete the reduction of Thrace;
(2) To open up the route westwards.