Bad weather behind Mongol army's sudden retreat from Hungary

Unfavourable weather conditions may have been behind the sudden, mysterious retreat of the mighty Mongol army from Eastern Europe in 1242, just when it seemed poised to conquer Hungary.
The sudden retreat by the Mongols has puzzled experts for hundreds of years.
The Mongol army had conquered their way out of Asia and into Russia, winning every battle they had fought. After making their way into Eastern Europe during the early 1200s, the army abruptly turned back to Russia, never to return.
Some have suggested it was Mongol politics, while others have maintained that armies in the Eastern Europe were putting up much more of a fight than the Mongols had expected.

In a new study, the researchers suggest that the reason might be much more mundane - simple bad weather.
Ulf Buntgen from the Swiss Federal Research Institute and Nicola Di Cosmo from the Institute for Advanced Study in the US studied tree ring data from Hungary and historical records, which showed that the weather during the time of the Mongol invasion was not well suited for an army travelling on horseback.

According to them, horses used by the Mongols survived by eating the grasses that were plentiful in Asia and Russia - grasses that were healthy and strong due to several years of good weather.

However, tree ring data, and some evidence in historical writings suggest that the winter of 1242 caused widespread freezing, 'Phys.Org' reported.
During spring, when the Mongols arrived, the snow melted and flooded the part of Hungary that sits at low elevations.
Melting ice and snow would have puddled, preventing the grass for growing very well that spring, leaving little for the horses to eat.
The water also made the land muddy, making travel very difficult. As a result, Mongols simply decided against progressing further because it did not seem worth the trouble, researchers suggest.
The study was published in the journal Nature.