The last battle with the Malmuks was when the Mongols were in decline - they were literally in their "roman decline years" The Mongol General was considered inept across a number of technical levels - as such it really came as no surprise.

They were not the Golden Horde of old by a long shot.

Re: The battle of Liegnitz 1241
 

It seems the mongols started to go down hill after the formation of the yuan dynasty in China.

Re: The battle of Liegnitz 1241
 

I'd argue that it was due to internal issues more than external issues. The family was divided, they had become indolent, and the grandsons lacked the drive of the Grandfather. None of them were military geniuses like Genghis, Khublai or Subodai.

By the time that they were beaten by the Mamluks, they really were a shadow of a force. An oriental version of the decline of Rome.

Divided by religion, sibling rivalry, and a lack of purpose. China's emergence through the Yuan was just another straw to break the camels back.

Re: The battle of Liegnitz 1241
 

It appears that the death of ghengis was the turning point then. It is the same problem with any great leader, it is impossible to follow. And it seems that these major war based societies only lasted aslong as there was a strong absolute ruler.