Mongol invasions

I've just been watching a documentary on the Mongol invasion of Japan.  Kubilai's haste and impatience spelled the beginning of the end for the empire, but I picked up some interesting facts:

Mongols seemed to have used one of the world's first hand grenades, or explosives - a hollowed out stone shell was filled with shards of metal then gunpowder, the hole in the top was stuffed with a cloth wrapped in string and lit, then thrown.  This would have terrified the Samurai defenders as they had not seen such a thing (as would the Turkish composite bow caused much havoc).

But it turned out that the superior skill of the Samurai in close combat and the poorly constructed Mongol fleet (built by newly conquered Chinese workers pressganged into service) and the 'divine wind' spelled doom despite the commanders, Arikhan, skill at land warfare.

I'm really interested in getting some more info about not just the invasion but more so about the Mongol invasion and defeat of China, can anyone give me some good information about that please? Thanks.

You can read about the Mongol invasion of Song china in www.chinahistoryforum.com

I didn't intend to double post my last posting.