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. Of these the first seems to have been but half accomplished; and though more success had been attained with the second, the failure to fully accomplish the first made it impossible for Darius to avail himself for the time being of the advantages won along that western route. He had found the Thracians, as others found them in later days, a much more difficult conquest than he had in all probability anticipated. It is now possible to consider whether the attempt to arrive at an ethnic frontier is the only object which may be suggested as guiding the policy with regard to Thrace. Despite the obscurity of the evidence, it seems clear that Darius intended the conquest of Thrace to be a prelude to further conquest westwards, and that, in pursuance of this design, European Greece was to be the next object of attack. Whether the conquest of Greece was to be merely a second stage in a great scheme of conquest along the northern shores of the Mediterranean, or whether it was merely designed for the purpose of securing the western borders of the empire by subjugating the free kinsmen of the most western subjects of the empire, cannot now be said, inasmuch as there is no evidence which throws light upon the question. It now remains to consider the evidence,— (1) As to Darius’ design of conquest westward; (2) As to the reasons why the attempts to carry it out was postponed for many years. The operations of Megabazos on the Strymon, followed by the demand for the submission of Macedonia, are certainly strong indications, if not conclusive evidence of, the design to get hold of the coast route to Northern Greece.