"Dr Ullmann needs no introduction to medievalists, who have long been indebted to his magisterial studies of political and theological thought in the Middle Ages ... all medievalists once again owe deep gratitude to Dr Ullmann, who makes them re-examine many too easily accepted conclusions and points them to many new avenues of thoughts, deserving exploration." - Journal of Ecclesiastical History"This is a work by a fine scholar writing primarily for scholars; but anyone interested in our modern problems of law and government will find study of this book well worth the effort." - Daily Telegraph"Discerning students of modern political institutions will realize that this study raises questions that were relevant way beyond the Middle Ages. The volume will be of interest for both graduate students and faculty alike." - Lavinia Stan, The European Legacy: Toward New Paradigms