signor Ghilarducci of the Archivio arcivescovile in Lucca for his
great kindness.

Numerous colleagues and friends have aided this project. David
Abulafia, Steven Epstein, Benjamin Kedar, and M. S. Omron fur-
nished valuable information. In addition, Ben was an excellent
guide in Jerusalem. Jeremy Johns and H. Houben were most help-
ful, too. Franco Cardini, Paolo Delogù, Giosuè Musca (the Direc-
tor of the Centro di Studi normanno-svevi at the Università di
Bari), and Cataldo Roccaro (of the Officina di Studi Medievali in
Palermo) were kind enough to invite me to give papers based on
this research. James John came through in a number of emergencies.
Kenneth Pennington and Donald Queller read the entire manu-
script at different stages in its development and made important
contributions to its improvement. Mrs. Jane Frost typed the manu-
script. Michael Markowski assisted with the computer study and
the bibliography. Finally, my wife and children have continued the
support I have received from them for many years.

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