The late F.L. Ganshof was professor emeritus of Medieval History, University of Ghent. Philip Grierson is professor emeritus of History, Cambridge University.
'He has a complete mastery of his material, sure historical judgment, creative imagination, and a gift for clear and precise exposition. A subject that is often treated in rather abstract terms is here given reality and concreteness ...' (about a reprint of the 3rd edition published in 1964 by F.L. Ganshof.) -- Sidney Painter Speculum