They tended to make an example of the first city they encountered, killing the populace, torching the buildings and making mountains of skulls. After such a display, the terrified remaining cities would be quick to send out emissaries to parlay. It may go out without saying, but don't expect a lot of allies. This is a campaign of world conquest. The best you can hope for are puny nations that will surrender immediately upon seeing your horde rather than risk facing your wrath.
Several heroes appear during the course of the campaign.
The great Mongolian general, Subotati Ba'atur of the Reindeer People appears in two scenarios, along with his hunting wolves. On the opposing side are the treacherous Kushluk and the conniving Khwarazm Shah. Kushluk is a fellow Mongol, so expect to pit your skirmishers against his horse archers. Khwarazm, on the other hand, is Persian, so you may be struggling to find a Mongol unit that can easily counter War Elephants. Remember that Mongols were masters of feints, deceit and trickery.