There have been a number of nomadic peoples in the recent past in the vast expanses of Eurasia - Kazakhs, Buryats, Tuvans, Altaians and some Bashkirs. The Kalmyks are one of them. However, Kalmyks are the only nomads that in historically documented times have made two trans-continental migrations: in the beginning of XVII century from Central Asia (Western Mongolia) to Eastern Europe (the shores of river Volga), where they founded their khanate, and at the end of XVIII century from the banks of the Volga back to their historic homeland of Western Mongolia. The Kalmyks thus repeated the traditional migration route for nomads (Scythians, Sarmatians, Huns and Tatar-Mongols) of previous eras (Early Iron Age and Middle Ages).
The change of the ethnic name from Oirats to Kalmyks in the course of migration is repeated by facts known from ancient history. For example, Yuezhi having left Central Asia for the Eastern European steppes were known as Alans, Kimaks, and having settled in the lower reaches of the Volga became known as Polovetses. This makes it possible to consider the history of Kalmyks in the context of world history as the last nomadic wave from the depths of Asia to Europe.
The reason for the expansion of nomads from the East to the West should be sought in the specifics of their nomadic economy. At certain historical intervals, as a result of favorable climatic conditions, the nomads of the Central Asian steppes accumulated large numbers of livestock. Even with slight climatic fluctuations towards aridity, there was a sharp shortage of pastures, and some of the nomads were pushed out of the region in search of new pastures. At the same time, the most powerful tribal unions, confident in their ability to conquer, set out in search of better pastures and new markets for their livestock. That is, in brief, the mechanism of all nomadic migrations.
For example, historians point to a whole complex of political and socio-economic problems as a reason for the departure of the Oirat from Central Asia to the Volga River. However, another manifestation of the global historical-ecological pattern can be seen in the compounding of this complex of problems. The migration of Kalmyks to the West can be compared in one sentence with the movements of ancient and medieval nomads, thus determining their place of destiny in the global historical process.