It was calculated that there were in the city twenty thousand armed inhabitants and forty thousand men in garrison, the most valiant and most fanatical Mussulmans that Egypt could furnish.

According to William of Tyre, the most judicious and the best informed of the contemporary historians, "When the crusaders pitched their camp over against Jerusalem, there had arrived there about forty thousand persons of both sexes, of whom there were at the most twenty thousand foot, well equipped, and fifteen hundred knights." Raymond d'Agiles, chaplain to the count of Toulouse, reduces still further to twelve thousand the number of foot capable of bearing arms, and that of the knights to twelve or thirteen hundred.

This weak army was destitute of commissariat and the engines necessary for such a siege.

Before long it was a prey to the horrors of thirst.

"The neighborhood of Jerusalem," says William of Tyre, "is arid; and it is only at a considerable distance that there are to be found rivulets, fountains, or wells of fresh water.