A historical book written by Imad Al -Din Al -Katib, in which he mentioned the events related to the Crusades and the conquest of Jerusalem from 583 AH until the year 589 AH, which is considered one of the important historical sources to understand the history of the Crusades during the era of Salah al -Din al -Ayyubi, written in an epic tone, the author said in its introduction: "And I dictated a second migration, which is the migration of Islam to Jerusalem, and these kept the two migrations and opposite the two balls." It also contains historical information about the holy places such as the Al -Aqsa Mosque, the Jewish temples, the Dome of the Rock Mosque, etc., and on some geographical information, such as the distance between cities or battle sites Important historical.