The Jewish defenders of Jerusalem retreated to their synagogue to "prepare for death" once the Crusaders had breached the outer walls of the city during the siege of 1099. The chronicle of Ibn al-Qalanisi states that the building was set on fire whilst the Jews were still inside. The Crusaders were supposedly reported as hoisting up their shields and singing "Christ We Adore Thee!" while they encircled the burning building." Following the siege, Jews captured from the Dome of the Rock, along with native Christians, were made to clean the city of the slain. Numerous Jews and their holy books (including the Aleppo Codex) were held ransom by Raymond of Toulouse. The Karaite Jewish community of Ashkelon (Ascalon) reached out to their coreligionists in Alexandria to first pay for the holy books and then rescued pockets of Jews over several months. All that could be ransomed were liberated by the summer of 1100. The few who could not be rescued were either converted to Christianity or murdered.