Voegelin's magisterial account of medieval political thought opens with a survey of the structure of the period and continues with an analysis of the Germanic invasions, the fall of Rome, and the rise of empire and monastic Christianity. The political implications of Christianity and philosophy in the period are elaborated in chapters devoted to John of Salisbury, Joachim of Flora (Fiore), Frederick II, Siger de Brabant, Francis of Assisi, Roman...