BACKGROUND
In fall of 1187 Saladin's "12,000 professional cavalrymen [and] 30,000 volunteers" arrived at Jerusalem and began a two week siege, assaulting the walls with towers, arrows, rocks, and greek fire. During the first five days of the siege he attacked the walls around the western wall, from the Tower of David and Damascus Gate. After failing there he moved to the northern wall, where he finally breached the city and obtained a surrender.
Accounts of the siege don't tell us what formations Saladin used to attack the walls, which is unfortunately exactly what I want to know. My first thought was that I could make a reasonable guess from accounts of another siege he led in 1188, where his "soldiers advanced in waves establishing a shield wall [...] behind which their archers and crossbowmen kept up repeated volleys of arrows [and then the] assault troops [...] storm[ed] the walls with scaling ladders and ropes." Saladin's army attacked in multiple divisions over the course of the day.
This seems plausible (though if you think it's not then this question changes to why and what is). But even so, it still leaves one big question to my mind.
THE QUESTION
- Given the military thinking of his day, what would Saladin have likely done with the rest of his army, in particular the cavalry and horse-archers, as a division of his infantry attacked the walls?
Regarding the cavalry, my first thought was defending the infantry from enemy sorties, but I still don't know where you'd best position them for that, or how feasible it is for such big targets to be riding up to the walls. I also don't know what use if any the famous Turkish horse-archers would be in a siege. Finally, my guess is that Saladin's siege weapons would have been positioned behind his archers at near their maximum range, but I wanted to fact check that. Corrections to my thinking or examples from comparable battles are welcomed. Thanks for your time.