The article considers the peculiarities of the existence of a regional international order in the northern Black Sea region during the Scythian rule based on the analysis of the fourth volume of the work „History”, entitled „Melpomene” by the ancient Greek historian and writer Herodotus. Emphasis is placed on the coverage of the causes, course and results of the Persian king Darius I in Scythia described in the treatise in 513 B. C. As a result of the study, the author concludes that the fourth chapter of Herodotus' „History” of Melpomene allows us to shed light on the ancient international order that existed on the steppe outskirts of the ancient world, where Scythian tribes ruled during the period under study. Among the aspects considered by the author and useful from the point of view of research of the chosen problem, there are features of mutual relations between Scythians and their allies – Greeks. Based on the testimony of Herodotus, we can conclude that during the intensification of contradictions with the Persian Empire of the Achaemenids in the VI century B.C. and the beginning of the military conflict with it, relations between Greece and Scythia move to a new, qualitative level. There is, in fact, a deepening of relations to the level of military-political alliance directed against the Persian king Darius I. There is also evidence of local Scythian allies – neighbors, some of whom refused to help them in the fight against the Persians, some – supported. Support for the latter, not only allowed to increase the army, but also allowed to wage a war of attrition, which provided for constant retreat, including in the territory of the Allies. It can be concluded that due to effective allied cooperation with local tribes, the Scythians succeeded in the main strategic task of this war – to create a threat to the bridge over the river Istra. This circumstance, which posed a risk for Darius to be cut off from his Caucasian possessions, forced the Persian ruler to retreat.