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Short-term disasters such as clusters of droughts or cold spells, lasting for just a decade or two, can induce food shortages, famines, and violence and create waves of refugees. Climatically enforced migrations can affect complex societies and, in extreme cases, even topple established bureaucracies. But the measurement of indirect signals (proxies), which is limited by the multidecadal range of radiometric dating or by the poor distribution of the better-dated signals (such as series of tree-rings, lacustrine varves, ice-cores, etc.), is often insufficient to determine the extent to which such natural disasters were the causes of particular human events in history. The introduction of historical evidence, however, can change the resolution of such indirect reconstructions and enable a more balanced and comprehensive assessment. Such an approach indicates that intense cold and other short-term climatic changes were largely responsible for the collapse of the Liao dynasty in Mongolia and northern China.