herm the 1st siege batle that genghis khans fought in china he ended up loosing half of his forçes according to the sources and thats because he had some engineers and a mercenary army provided by the chinese when they tryed to stop him from going around the great wall (i guess the chinese never had heard of the epirot troubles with the keltoi mercenaries or they wouldn´t have recruited an entire mercenary army) or else he probably would have lost due to impatiente (in the end the city surrendered after having eaten all the dogs animals and many sources claim their own dead where eaten)