What Is the War Between the Christians and the Crusaders?

In 1182, Saladin launches a new invasion of the Kingdom of Jerusalem. A crusader army marches out to meet him and the two sides face off on an extremely hot July day. The Franks have stockpiled provisions in their castle but they can't sustain it for long enough. Now he has another trick up his sleeve. He scheduled a rendezvous with the Egyptian fleet which is due to sail up the coast that summer. But now there's a problem as supplies quickly start to run out. It's also very hot so he needs to disperse his men for water but he can't. And basically the only way that Saladin can feed his army is by scattering and letting them forage