Videos: Jerusalem is conquered in the First Crusade
It was decided that the assault should begin during the night of 13-14 July…. The first task of the assailants was to bring their wooden castles right up to the walls…. All night long and during the day of the 14th the Crusaders concentrated on their task, suffering heavily from the stones and the liquid fire of the defence, and answering with a heavy bombardment from their own mangonels.
Godfrey and his brother, Eustace of Boulogne, commanded from the upper storey. About midday they succeeded in making a bridge from the tower to the top of the wall; and two Flemish knights, Litold and Gilbert of Tournai, led the pick of the Lotharingian army across, followed soon by Godfrey himself. Once a sector of the wall was captured, scaling ladders enabled many more of the assailants to climb into the city.
A Letter from the First Crusade: The Conquest of Jerusalem, 1099
While Godfrey remained on the wall encouraging the newcomers and sending men to open the Gate of the Column to the main forces of the Crusade, Tancred and his men, who had been close behind the Lorrainers, penetrated deep into the city street. The Moslems, seeing their defences broken, fled towards…where the Dome of the Rock and Mosque of al-Aqsa stood, intending to use the latter as their last fortress. But they had no time to put it into as state of defence. As they crowded in and up on the roof, Tancred was upon them.
Steven Runciman, The First Crusade (Cambridge, UK: Cambridge University Press, 1951), 226-7.