As this book is the result of my doctoral research, I would like to thank first of all Chris Wickham, my supervisor, for the unceasing support (from an academic but also personal point of view) he gave me. As all graduate students know, a good supervisor is fundamental for a doctorate to be a positive, enriching experience, and I could not have asked for any better. Paolo Grillo has been a patient reader and a constant provider of good advice. Together with Rinaldo Comba, he has helped me discover the complex and fascinating world of the Italian communes, and I owe both of them much gratitude for this. Other academics that have mentored me in different capacities, and who I would like to thank are: Michele Pellegrini, Philip Booth, Ian Forrest, Gervase Rosser, John Blair, John Arnold, Bernard Gowers, Frances Andrews, Piroska Nagy, and Hannah Skoda. I have been very lucky to receive the support of so many great scholars