Long time, historians believed that there are long periods of drought caused the Mongols to invade neighboring lands, reaching eventually form in XIII century, a huge empire that stretched over much of Eurasia . But new findings suggest that, on the contrary, the “engine” of these achievements would have been wet climate of the period.
Mongol hordes could invade and conquer large territories due to wet climate, which favored the growth of vegetation and provided, so Mongols “fuel” needed these large-scale military operations: food for their horses.
Taking as a means of traveling horse, Mongolian invaders needed large amounts of plant biomass to feed their animals. Dendrochronology study (based on growth rings of trees) in the past climate of Mongolia, recent study conducted by an international team of researchers, indicate that in the thirteenth century there was a period of more intense precipitation, which stimulated growth herbaceous vegetation, allowing Mongol horsemen to migrate long distances and maintain a large number of horses used for transportation, and other herbivores that are used as food.
Researchers have studied the rings of trees growing on volcanic soils in Mongolia, in arid regions today. Counting growth rings and measuring their thickness, can be known precisely when in the past there were periods when drought and high rainfall were.
Although research is only beginning, seem to show that exactly the period of maximum expansion of the Mongol Empire in the days of Genghis Khan and his successor Ögedei Han (XIII century AD), there was a wet period: rings formed in that period are semnficativ wider than the other, which were formed in dry years.
Historians of ecghpa researchers now studying Chinese and Mongolian documents of that period to determine if records exist to confirm their hypothesis.
Source: Live Science