Historia

William's great work is a Latin chronicle, written between 1170 and 1184.[36] It contains twenty-three books; the final book, which deals with the events of 1183 and the beginning of 1184, has only a prologue and one chapter, so it is either unfinished or the rest of the pages were lost before the whole chronicle began to be copied. The first book begins with the conquest of Syria by Umar in the seventh century, but otherwise the work deals with the advent of the First Crusade and the subsequent political history of the Kingdom of Jerusalem. -- Wikipedia