William of Tyre, A History of Deeds Done Beyond the Sea, transl. E.A. Babcock and A.C. Krey (New York: Columbia Univ. Press, 1943), pp. 17, 22. For a very readable account of Ashkelon in the Crusader period, see Meron Benvenisti, The Crusaders in the Holy Land (Jerusalem: Israel Universities Press), pp. 114–130.