Amidst the numerous tribes, between the Danube and the Aegean sea – who all bore the generic name of Thracians, though each had a special name besides – the Odrysians were at this time the most warlike and powerful. The Odrysian king Teres, father of Sitalkes, had made use of this power to subdue and render tributary a great number of these different tribes, especially those whose residence was in the plain rather than in the mountains. His dominion, the largest existing between the Ionian sea and the Euxine, extended from Abdera or the mouth of the Nestus in the Aegean sea, to the mouth of the Danube in the Euxine; though in seems that this must be understood with deductions, since many intervening tribes, especially mountain tribes, did not acknowledge his authority. Sitalkes himself had invaded and conquered some of the Paeonian tribes who joined the Thracians on the west, between the Axius and the Strymon. Dominion, in the sense of the Odryssian king meant tribute, presents, and military force when required. With the two former, at least, we may conclude that he was amply supplied, since his nephew and successor Seuthes (under whom the revenue increased and attained its maximum) received 400 talents annually in gold and silver as tribute, and the like sum in various presents, over and above many other presents of manufactured articles and ornaments. These latter came from the Grecian colonies on the coast, which contributed moreover largely to the tribute, though in what proportions we are not informed. Even Grecian cities, not in Thrace, sent presents to forward their trading objects, as purchasers for the produce, the plunder, and the slaves, acquired by Thracian chiefs or tribes. The residence of the Odrysians properly so called, and of the princes of that tribe now ruling over so many of the remaining tribes, appears to have been about twelve days’ journey inland from Byzantium, in the upper regions of the Hebrus and Strymon, south of Mount Haemus  and  north-east of Rhodope. The Odrysian chiefs were connected by relationship more or less distant with those of the subordinate tribes, and by marriage even with the Scythian princes north of the Danube: the Scythian prince Ariapeithes had married  the daughter of the Odrysian Teres, the first who extended the dominion of his tribe over any considerable portion of Thrace.

   The natural state of the Thracian tribes in the judgement of Herodotus, permanent and incorrigible – was that of disunion and incapacity of political assotiation; were such association possible (he says), they would be strong enough to vanquish every other nation – though Thucydides considers them as far inferior to the Scythians. The Odrysian dominion had probably not reached, at the period when Herodotus made his inquiries, the same development which Thucydides describes in the third year of the Peloponnesian war, and which imparted to these tribes a union, partial indeed, and temporary, but such as they never reached either before or afterwards. It has been already mentioned that the Odrysian prince Sitalkes had taken for his wife (or rather for one of his wives) the sister of Nymphoderus, a Greek of Abdera; by whose mediation he had been made the ally, and his son Sadokus even a citisen, of Athens. He had farther been induced to promise that he would reconquer the Chalkidians of Thrace for the benefit of the Athenians, - his ancient kinsmen, according  to the mythe of Tereus as interpreted by both parties. At the same time, Perdikkas king of Macedonia had offended him by refusing to perform a promise made of giving him his sister in marriage – a promise made as consideration for the interference of Sitalkes and Nymphodorus in procuring for Perdikkas peace with Athens, at a moment when he was much embarrassed by civil dissensions with his brother Philip. The latter prince, ruling in his own name (and seemingly independent of Perdikkas) over a portion of the Macedonias along the upper course of the Axius, had been expelled by his more powerful brother, and taken refuge with Sitalkes. He was now apparently dead, but his son Amyntas received from the Odrysian prince the promise of restoration. The Athenians, though they had ambassadors resident with Sitalkes, nevertheless sent Agnon as special envoy to concert arrangements, for his march against the Chalkidians, with which an Athenian armament was necessary to be liberal in presents both to himself and to the subordinate chieftains who held power dependent upon him. Nothing could be accomplished among the Thracians except by the aid of bribes, and the Athehians were more competent to supply this exigency than any other people in Greece. The joint expedition against the Chalkidians was finally resolved.

  But the forces of Sitalkes, collected from many different portions of Thrace, where tardy in coming together. He summoned all the tribes under his dominion between Haemus, Rhodope, and the two seas: the Getae between Mount Haemus and the Danube, equipped like the Scythians  (their neighbours on the other side of the river) with bow and arrow on horseback, also joined him, as well as the Agrianes, the Laeaei, and the other Paeonian tribes subject to his dominion. Lastly, several of the Thracian tribes called Dii, distinquished by their peculiar short swords, and maintaining a fierce independence on the heights of Rhodope, were tempted by the  chance of  plunder, or the offer of pay, to flock to his standard. Altogether his army amounted, or was supposed to amount, to 150,000 men – one-third of it cavalry, who were for the most part Getae and Odrysians proper. The most formidable warriors in his camp were the independent tribes of Rodope. The whole host, alike numerous, warlike, predatory, and cruel, spread terror amidst all those who were within even the remote possibilities of its march.

     Starting from the central Odrysian territory, and bringing with him Agon and the other Athenian envoys, he first crossed the uninhabited mountain called Kerkine, which divided the Paeonians on the west from the Thracian tribes called Sinti and Maedi on the east, until he reached the Paeonian town or district called Doberus; it was here that many troops and additional volunteers reached him, making up his full total. From Doberus, probably marching down along one of the tributary streams of the Axius, he entered into that portion of Upper Macedonia which lies along the higher Axius, and which had constituted the separate principality of Philip. The presence in his army of Amyntas, son of Philip, induced some of the fortified places, Gortynia, Atalante, and others, to open their gates without resistance, while Eidomenh was taken by storm, and Europus in vain attacked. From hence he passed still farther southward into Lower Macedonia, the kingdom of Perdikkas; ravaging the territory on both sides of the Axius even to the neighbourhood of the towns Pella and Kyrrhus; abd apparently down as far south as the mouth of the river and the head of the Thermaic Gulf. Farther south than this he did not go, but spread his force over the districts between the left bank of the Axius and the head of the Strymonic gulf, - Mygdonia, Krestonia, and Anthemus - while a portion of his army was detached to overrun the territory of the Chalkidians and Bottiaeans. The Macedonians under Perdikkas, renouncing all idea of contending on foot against so overwhelming a host, either fled or shut themselves up in the small number of fortified places which the country presented. The cavalry from Upper Macedonia, indeed, well-armed and excellent, made some orderly and successful charges against the Thracians, lightly armed with javelins, short swords, and the pelta or small shield, - but it was presently shut in, harassed on all sides by superior numbers, and compelled to think only of retreat and extrication.

   Luckily for the enemies of the Odryssian king, his march was not made until the beginning of winter – seemingly about November or December. We may be sure that the Athenians, when they concerted with him the joint attack upon the Chalkidians, intended that it should be in a better time of the year. Having probably waited to hear that his army was in motion, and waited long in vain, they began to despair of his coming at all, and thought it not worth while to despatch any force of their own to the spot. Some envoys and presents only were sent as compliments, instead of the cooperating armament. And this disappointment, coupled with the severity of the weather, the nakedness of the country, and the privations of his army at that season, induced Sitalkes soon to enter into negotiations with Perdikkas; who moreover gained over Seuthes, nephew of the Odrysian prince, by promising his sister Stratonike in marriage, together with a sum of money, on condition that the Thracian host should be speedily withdrawn. This was accordingly done, after it had been distributed for thirty days over Macedonia; during eight of which days his detachment had ravaged the Chalkidic lands. But the interval had been quite long enough to diffuse terror all around. Such a host of fierce barbarians had never before been brought together, and no one knew what direction they might be disposed to carry their incursions. The independent Thracian tribes (Pnaei, Odomantes, Droi and Dersaei) in the plains on the north-east of the Strymon, and near Mount Pangaerus, not far from Amphipolis, were the first to feel alarm lest Sitalkes shoud take the opportunity of trying to conquer them. On the other side, the Thessalians, Magnetes, andother Greeks north of Thermopylae, apprehensive that he would carry his invasion farther south, began to organise means for resisting him. Even the general Peloponnesian  confederacy heard with uneasiness of this new ally whom Athens was bringing into the field, perhaps against them. All such alarms were dissipated, when Sitalkes, after remaining thirty days, returned by the way he came, and the formidable avalanche was thus seen to melt away. The faithless Perdikkas, on this occasion, performed his promise to Seuthes, having drawn upon himself much mischief by violating his previous similar promise to Sitalkes.