I beat the battle of Jaffa! It took like ten tries, but I did it! Here's an idea that worked for me, if anyone's interested. In the beginning, right away as soon as you can, move all your ranged units like archers and sailors right up to the gate, and pack them in tight. Then, take all your spearmen, and form walls around them, using the castle as the rear wall. That way you form kind of a half hexagon of spearmen and such, with a big bundle o' death from above inside all wrapped up pretty! Then use your ranged units to hammer anyone who gets close non-stop. Even this close formation didn't work a few times. What really made me win was capturing the enemy sultan. This lowered enemy morale, so I charged at their units with everything I had as some were indecisive or fleeing. They could have crushed me, but with their low morale, and my charging forces, they kept right on runnin' !