Much of the Historia was finished before William left to attend the Lateran Council, but new additions and corrections were made after his return in 1180, perhaps because he now realized that European readers would also be interested in the history of the kingdom.
《历史》的大部分在威廉动身去参加拉特朗公会议之前就写好了，但是在他1180年返回以后又做了新的添加和修正，也许因为他这时意识到欧洲的读者也会对王国的历史感兴趣。