The Course of the Campaign. 514 BC.—Darius throughout this campaign showed his usual military capacity. Before setting his great army in motion, he ordered the Satrap of Cappadocia to make a raid on the northern coast of the Black Sea, mainly with a view to capturing some prisoners. This preliminary operation was carried out with complete success, and among the captives was the brother of a local chief, whose information must have been of considerable value.
The great expedition started about 512 BC crossing the Bosphorus, in the neighborhood of modern Constantinople, on a bridge of boats built by the Greek cities of Asia Minor and guarded by the Greek cities of the neighborhood. Thence, keeping near the coast of the Black Sea and receiving the submission of the Thracians, of whom only one tribe attempted resistance, the huge force, accompanied by the fleet, marched to the delta of the Danube. At the head of the delta, a second bridge of boats was constructed by the tyrants of the Ionian cities, to whose care it was entrusted; and Darius, after crossing it, launched into the unknown steppe. Had the campaign been made in connection with a future expedition to be undertaken against Greece, it would seem extraordinary that the distance already traversed and the magnitude of the Danube should not have proved to the Great King that the Scythians were extremely unlikely to raid down to the Hellespont in force. In the march beyond the Danube there was apparently no adequate objective, although many flocks and herds must have been captured. The Scythians, whose mobility, like that of all nomads, was great, kept away from his line of march as far as possible. Had serious operations eastward been intended, the fleet would obviously not have been left in the Danube.
Herodotus, whose delightful pages deal fully with this campaign, states that Darius sent an emissary to the Scythian king with the following message :
“Thou strange man, why dost thou keep on flying before me, when there are two things thou mightest do so easily? If thou deemest thyself able to resist my arms, cease thy wanderings and come, let us engage in a battle. Or if thou art conscious that my strength is greater than thine, even so shouldest thou cease to run away : thou hast but to bring thy lord earth and water, and to come at once to a conference”.
To this message the Scythian king replied :
“This is my way, Persian, I never fear men or flee from them ... Earth and water I do not send; but thou shalt soon receive more suitable gifts”.
These were sent by a herald, and proved to be a bird, a mouse, a frog, and five arrows. The herald, questioned as to their signification, replied that the Persians, if wise, would find out themselves. At a council, Darius expressed the opinion that the Scythians intended to surrender, and that the mouse and frog symbolized earth and water respectively. His father-in-law, Gobryas, however, explained that the real meaning was as follows :
“Unless, Persians, ye can turn into birds and fly into the sky, or become mice and burrow underground, or make yourselves frogs and take refuge in the fens, ye will never make your escape from this land, but die pierced by our arrows”.
The fact appears to be that the expedition became a military promenade, as the Persians were unable to secure a decisive engagement. After a march of some two months, during the course of which its losses might have been considerable from desultory attacks, lack of supplies, and sickness, the army returned to the Danube, where the Scythians had tried to induce the Greeks to destroy the bridge. The ‘tyrants’ debated on this question, but came to the sapient conclusion that their own position depended on the support of the Great King, and they consequently remained loyal to their trust.
The Annexation of Thrace and the Submission of Macedonia.—Darius recrossed the Danube in safety. On the way back to Sardes he detached a force of 80,000 men for service in Europe. These troops not only reduced the Greek cities of Thrace which had revolted, but also received the submission of Macedonia, and; thereby with little effort brought the boundaries of the Persian Empire into contact with northern Greece. The conquest of Thrace was the main result of the campaign.