The next phase of the Iranian-Scythian hegemony is linked, in the western part of the steppes, to the Sarmatians.
We have seen that Herodotus mentioned, on the eastern margins of European Scythia, the Sauromates. The name is Iranian and means “black furs (*coma-) (*sau-)”, with the nominative plural ending -ta typical of Scythian dialects. The Melanchlaines also cited by Herodotus are undoubtedly the same people, under a name roughly translated into Greek. The archaeological expression of the Sauromates is the culture developed from the 7th to the 4th century BC in the Russian steppes from the Don to the Urals, and in western Kazakhstan. This pastoral and warrior culture, socially differentiated, conforms to the classical Scythian model. It gives a place of honor to women even in warlike activities, which corroborates the words of Herodotus and founds the legendary traditions on the Amazons, known both among the Greeks and in Ossetian epic poetry. 20% of female tombs from the 6th-4th centuries BC. AD contain weapons and horse harness
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The influence of the Sauromates extends to the 5th-4th centuries BC . AD to part of the northern Caucasus, as far as the Kouma and the Terek (kurgans of Atchikoulak and Bajigan). In the 4th century BC, the Sauromates begin to cross the Don and the northern Donets and come up against the Scythians of Ukraine. Between the 4th and 2nd centuries, certain groups advanced as far as the Dnieper. At that time, Greek writers speak indiscriminately of Sauromates, Sarmatians (Eudoxe, Strabo), then Sarmatians (Polybius). Archaeologically, this expansion and terminological variations correspond to the spread of the Prokhorovka culture, which appeared in the 4th century in the Urals and rapidly spread westward. This culture is related to that of the earlier sauromate phase, but apparently includes other contributions (Central-Asian?).
We can therefore think that the historical Sarmatians were formed from the Sauromates, whose name they kept (despite certain phonetic difficulties, these are certainly two variants of the same name), but by assimilating other more eastern Iranian groups. Anyway, the Sarmatians never formed a single whole, and they appear from the outset divided into tribes or tribal confederations.
Such groups are mentioned in the decree of the city of Olbia in favor of Protogene, such as the Eatot (*khchaya- "royal") or EavSapatat (*saudâra-ta "carriers of black", which recalls the etymology of name of the Sarmatians themselves).
The westward thrust of the Sarmatians is accentuated from the 2nd century BC. It coincides with the spread of what archaeologists call “middle Sarmatian culture”, which succeeds that of Prokhorovka over a significantly expanded territory. This expansion is contemporaneous with that of the Parthians (with strong "Scythian" affinities) in Persia, and the Saces and Tocharians further to the east.
Echoes of the conquest of the Ukrainian steppes by the Sarmatians are found in Diodorus of Sicily, who wrote in the 1st century BC. J.-C. but reports previous events. For Diodorus, the Sarmatians “devastated a considerable part of Scythia and, exterminating the vanquished to the last, transformed the greater part of the country into a desert”. As with the Cimmerians and Scythians five centuries earlier, one may wonder if this picture is realistic. Scythians will survive in any case until the first centuries of our Era, towards the mouth of the Danube (“Little Scythia”) and especially in Crimea. The late Scythian culture of Crimea shows obvious Sarmatian influences.
The modalities of this conquest are unknown; we ignore both the balance of power between Sarmatians and Scythians and the political situation of the latter before their defeat. A gradual weakening of the Scythian kingdom(s) after the wars against the Macedonians and the death of the great king Atheas (339 BC) has been invoked, or the military superiority that the Sarmatians would have gained from their heavy armored cavalry, if it ever existed in numbers at that time.
Be that as it may, the Sarmatians dominate from the beginning of the 1st century BC the entire Ukrainian-Russian steppe, from the Danube to the Urals, and part of Ciscaucasia. In this last region, they continue the process of determined itineraries. The radius of seasonal movements can reach 100 to 400 km, according to estimates made in the Volga-Urals zone. The transgression of often ill-defined boundaries, the theft of cattle, must be permanent causes of war. With the Sarmatians, moreover, family heraldic signs appeared in the steppes, which ethnographers designate by the Turkish-Mongolian name of tamga, and which serve to mark livestock and household objects, to indicate crossing points, etc. The diversity of funerary furniture shows that society is clearly hierarchical. The large tribal confederations are led by “kings” who are above all figured as warlords. There certainly exists, above the mass of free men (slavery does not seem to represent an important reality), an elite of “nobles”. This is the pattern that we already reconstituted among the Scythians, and it is the one that was perpetuated until modern times in the Caucasus
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Women can occupy high positions (a Sarmatian queen, Amagê, is mentioned in the 2nd century). Women's graves no longer contain weapons as in previous periods, but funerary furniture often includes half-utilitarian, half-ritual objects (metal mirrors, portable pot altars) which may suggest the service of certain cults linked to domestic fire.
In the military field, without absolutely innovating, the Sarmatians developed tactics and types of weapons little used by the Scythians. Thus, "the chiefs and all the nobles", as Tacitus calls them, form a heavy cavalry of cuirassed lancers (cataphractaries), which act by shock at the decisive moment of a battle, when the ground has been prepared by the harassment of the mounted archers (provided by the mass of non-noble freemen). It is undoubtedly for these heavy horsemen that the long sword with discoidal hilt spreads, concurrently with the usual short sword with annular pommel
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Religion is known only through burials and the traces of funeral rites they may contain. They are generally mounds (kourgans) covering individual or collective graves of variable structure. In particular, attempts have been made to attribute to the Roxolans a particular type of pit where the body is placed diagonally, but the fact is disputed. The deceased are always accompanied by furniture proportional to their status. Sarmatian art is based on the same animal traditions as that of the Scythians, but it did not experience the same Hellenization. He has a predilection for inlays of colored materials (semi-precious stones, glass), which are also found in other parts of the ancient Iranian world, such as in Bactria.