The first study which I produced of Baldus' political thought was my Ph.D. dissertation. After a lapse of some years I returned to the subject in order to publish a full-scale treatment. This book represents my recent thought about Baldus'political ideas and entirely supersedes my dissertation. I found that my own ideas about Baldus and indeed my understanding of medieval political thought had radically changed in the interim with the result that this book is very much a new venture: I have entirely rewritten and rethought my interpretation of Baldus. Not only that, I have also included much more information from the primary sources, both from Baldus himself and from other jurists.

In order to reach a wider audience I have in the text translated into English all the quotations from primary sources. The original Latin versions will be found in the Appendix. In order to save space I have made shortened references to books and articles in the footnotes: full details will be found in the bibliography. In referring to the Corpus Iuris Civilis I have followed the edition of T. Mommsen, P. Krueger, R. Schoell and W. Kroll as regards the numbering of books, titles, laws and novellae. In quoting, however, from the Corpus Iuris Civilis I have used the text of the Venice, 1497–8, edition because this is derived from the medieval Vulgate version (littera Bononiensis).