[361] See Xenophon, Anabas. vii, 3, 16; 4, 2. Diodorus (xii, 50) gives the revenue of Sitalkês as more than one thousand talents annually. This sum is not materially different from that which Thucydidês states to be the annual receipt of Seuthes, successor of Sitalkês,—revenue, properly so called, and presents, both taken together. Traders from Parium, on the Asiatic coast of the Propontis, are among those who come with presents to the Odrysian king, Mêdokus (Xenophon _ut supra_). [362] Xenoph. Anabas. _l. c._ [363] Herodot. iv, 80. The natural state of the Thracian tribes—in the judgment of Herodotus, permanent and incorrigible—was that of disunion and incapacity of political association; were such association possible, he says, they would be strong enough to vanquish every other nation,—though Thucydidês 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 Thucydidês describes in the third year of the Peloponnesian war, and which imparted to these tribes an union, partial indeed and temporary, but such as they never reached either before or afterwards. It has been already mentioned that the Odrysian prince Sitalkês, had taken for his wife, or rather for one of his wives, the sister of Nymphodôrus, a Greek, of Abdêra; by whose mediation he had been made the ally, and his son Sadokus even a citizen, of Athens,—and had been induced to promise that he would reconquer the Chalkidians of Thrace for the benefit of the Athenians,[364]—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 Sitalkês and Nymphodôrus in procuring for him 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 Macedonians along the upper course of the Axius, had been expelled by his more powerful brother, and taken refuge with Sitalkês: he was now apparently dead, but his son Amyntas received from the Odrysian prince the promise of restoration. The Athenians had ambassadors resident with Sitalkês, and they sent Agnon as special envoy to concert arrangements for his march against the Chalkidians, with which an Athenian armament was destined to coöperate. In treating with Sitalkês, it 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,[365] and the Athenians were more competent to supply this exigency than any other people in Greece. The joint expedition against the Chalkidians was finally resolved.