In addition, Kalmyk allegiance was often nominal, as the Kalmyk Khans practiced self-government, based on a set of laws they called the Great Code of the Nomads (Iki Tsaadzhin Bichig).
The Kalmyk Khanate reached its peak of military and political power under Ayuka Khan (1669–1724).
They reached the lower Volga region in or about 1630.
That land, however, was not uncontested pastures, but rather the homeland of the Nogai Horde, a confederation of Turkic-speaking nomadic tribes.
Kalmykia has a cold semi-desert climate, with hot and dry summers and cold winters with little snow.
Successful military expeditions were also conducted in the Caucasus.
Average annual precipitation ranges from 170 millimeters (6.7 in) in the east of the republic to 400 millimeters (16 in) in the west.
The small town Utta is the hottest place in the whole of Russia.
Various reasons have been given for the move, but the generally accepted answer is that the Kalmyks sought abundant pastures for their herds.
Another motivation may have been to escape the growing dominance of the neighboring Dzungar Mongol tribe.