[22] The formation of genuine nomadic pastoralism itself happened in the early 1st millennium BC due to climatic changes which caused the environment in the Central Asian and Siberian steppes to become cooler and drier than before.

[36] Thanks to their development of highly mobile mounted nomadic pastoralism and the creation of effective weapons suited to equestrian warfare, all based on equestrianism, these nomads from the Pontic-Caspian Steppes were able to gradually infiltrate into Central and Southeast Europe and therefore expand deep into this region over a very long period of time,[37][30] so that the Chernogorovka-Novocherkassk complex covered a wide territory ranging from Central Europe and the Pannonian Plain in the west to Caucasia in the east, including present-day Southern Russia.

[42] Instead, the main grouping of Iranic nomads of Central Asian origin belonging to the Chernogorovka-Novocherkassk complex in the eastern parts of the Pontic Steppe were the Agathyrsi to the north of the Lake Maeotis.

[29] The reasons for the departure of the Cimmerians are unknown,[62] although they might possibly have migrated under the pressure from the Scythians, similarly to how various nomadic peoples drove each other into the peripheries of the steppes in Europe, West Asia and the Iranian Plateau during Late Antiquity and afterwards.

[69][74] The involvement of the steppe nomads in West Asia happened in the context of the then growth of the Neo-Assyrian Empire, which under its kings Sargon II and Sennacherib had expanded from its core region of the Tigris and Euphrates valleys to rule and dominate a large territory ranging from Que (Plain Cilicia) and the Central and Eastern Anatolian mountains in the north to the Syrian Desert in the south, and from the Taurus Mountains and North Syria and the coast of the Mediterranean Sea in the west to the Iranian Plateau in the east.

[75][76] Surrounding the Neo-Assyrian Empire were several smaller polities:[77][76] Beyond the territories under the direct Assyrian rule, especially in its frontiers in Anatolia and the Iranian Plateau, were local rulers who negotiated for their own interests by vacillating between the various rival great powers.

[75] This state of permanent social disruption caused by the rivalries of the great powers of West Asia thus proved to be a very attractive source of opportunities and wealth for the steppe nomads.

[83] Thus, the Cimmerians and Scythians became active in West Asia in the 7th century BC,[61] where they would vacillate between supporting either the Neo-Assyrian Empire or other local powers, and serve them as mercenaries, depending on what they considered to be in their interests.

[78][84][85] Their activities would over the course of the late-8th to late-7th centuries BC disrupt the balance of power which had prevailed between the states of Elam, Mannai, the Neo-Assyrian Empire and Urartu on one side and the mountaineer and tribal peoples on the other, eventually leading to significant geopolitical changes in this region.

[64][65][63] During the early phase of their presence in West Asia until the early 660s BC, the Cimmerians moved into Transcaucasia, which acted as their initial centre of operations:[2] after having passed through Colchis and western Caucasia and Georgia,[72][87] during the 8th century BC, the Cimmerians settled in a region located to the east of Colchis, in the areas of central Transcaucasia[88] to the immediate south of the Darial and Klukhor passes[89] and on the Cyrus river,[71] which corresponds to territory of Gori in modern-day central and southern Georgia.

[101] This attack therefore took the Urartians by surprise[102] and forced the governor of Uišini to ask for support from the king of the neighbouring small state of Muṣaṣir located on the Assyro-Urartian border region.

[122] In 705 BC, Sargon II led a campaign against a rebellious Neo-Assyrian vassal, the Neo-Hittite kingdom of Tabal in Anatolia, during which he probably also fought the Cimmerians, and was killed in battle against the Tabalian ruler Gurdî of Kulummu.

Therefore, the Mannaean king Aḫšēri (r. c. 675 – c. 650 BC) welcomed the Cimmerians and the Scythians as useful allies who could offer both protection and favourable new opportunities to his kingdom, which in turn allowed him to become an opponent of the Neo-Assyrian Empire, with him subsequently remaining an enemy of Sennacherib and his successors Esarhaddon and Ashurbanipal.

[148] Meanwhile, Mannai, which had been able to grow in power under Aḫšēri, possibly thanks to its adaptation and incorporation of steppe nomad fighting technologies borrowed from its Cimmerian and Scythian allies,[155] was able to capture the territories including the fortresses of Šarru-iqbi and Dūr-Illil from the Neo-Assyrian Empire and retain them until the c. 650s BC.

[156][145] Under Argišti II, Urartu attempted to restore its power by expanding to the east towards the region of Mount Sabalan, possibly to relieve the pressure on the trade routes across the Iranian Plateau and the steppes from the Scythians, Cimmerians, and Medes.

[185] This migration is archaeologically attested in the form of the expansion of the Scythian culture into this region,[2] although the further details of the exact time and trajectory through which the Cimmerians moved into Anatolia, and whether these movements consisted of a single group or of disparate divisions, are however unknown.

[199] According to a tradition later recorded by Stephanus of Byzantium, the Cimmerians found several tens of thousands of medimnoi of wheat in the underground granaries of the Phrygian village of Syassos that they used as food for a long time.

[222] Lower class Ionian Greeks and Carians affected by this Cimmerian invasion appear to have formed a significant part of the colonists who went to set up new settlements throughout the shore of the Black Sea in the 7th century BC, such as the colonies of Borysthenēs, Histria, Apollonia Pontica, Kallatis, and Karōn Limēn.

[228] The defeat of the Cimmerians by Gyges in turn weakened their allies, Mugallu of Tabal and Sandašarme of Ḫilakku, enough that they were left with no choice but to submit to the authority of the Neo-Assyrian Empire in c. 662 BC.

[243] In the 650s BC, the Cimmerians were allied to Urartu[202][129] and were serving as auxiliaries in the service of its king Rusa II, who was then attempting to attack the newly conquered Assyrian province of Šubria near the Urartian border.

[250] The Neo-Assyrian sources blamed Gyges's death on his own hubris, that is on his own independent actions, by claiming that the Cimmerians invaded Lydia and killed him as punishment for him providing Psamtik I with the troops he used to eliminate the other pro-Assyrian Egyptian kinglets and unify Egypt under his sole rule.

[251][214] After this attack, Gyges's son Ardys succeeded him as king of Lydia and resumed diplomatic activity with the Neo-Assyrian Empire with the hope of military support which Ashurbanipal again did not provide.

[253] After sacking Sardis, Lydgamis and Kobos led the Cimmerians and the Treres into invading the Greek city-states of the Troad,[128][2] Aeolia and Ionia on the western coast of Anatolia,[254] where they destroyed the city of Magnesia on the Meander as well as the Artemision of Ephesus.

[248][261][262] Dugdammî soon broke his oath and attacked the Neo-Assyrian Empire again, but during his military campaign he contracted a grave illness whose symptoms included paralysis of half of his body and vomiting of blood as well as gangrene of the genitals, and he consequently committed suicide in 640 BC[263] in Cilicia itself.

[202] It was also around this time that the last still-existing Syro-Hittite and Aramaean states in Anatolia, which had been either independent or vassals of the Neo-Assyrian Empire, Phrygia, Urartu, or of the Cimmerians, also disappeared, although the exact circumstances of their end are still very uncertain.

[280][272][281] And, following the defeat of the Cimmerians and the disappearance of these states, it was the new Lydian Empire of Alyattes which became the dominant power of Anatolia,[204][282] while the city of Sinope was re-founded[275][283] by the Milesian Greek colonists Kōos and Krētinēs.

[183] The first mention of the Cimmerians in Graeco-Roman literature dates from the 8th century BC in Homer's Odyssey,[298] which describes them as a people living in a city located at the entrance of Hades beyond the western shore of the Oceanus river which encircles the world, in a land towards which Odysseus sailed to obtain an oracle from the soul of the seer Tiresias, and which was covered with mists and clouds and therefore remained permanently deprived of sunlight although the Sun-god Helios sets there.

[44] These inconsistencies suggest that Herodotus's narrative of an eastern flight of the Cimmerians was a later folk tale invented by Greek colonists on the north shore of the Black Sea to explain the existence of ancient tombs, reflecting the motif of assigning old tombs and buildings with mythical heroes or with lost ancient valiant peoples, similarly to how the Greeks within Greece proper claimed similar remains had been built by the Pelasgi and the Cyclops,[47][44][184] or how later Ossetian tradition recounted the death of the Narts.

A similar structure is attested in mediaeval times among the Oguz Turks, whose single kingdom was divided into two wings each ruled by a member of the same dynasty and each made up of several tribes.

[218][62][185] The few known Cimmerian archaeological remains from the period of their presence in Anatolia include a burial from the village of İmirler in the Amasya Province of Turkey which contains typically Early Scythian weapons and horse harnesses.