Emily O’Brien is an associate professor in the Departments of History and Humanities at Simon Fraser University.

• IntroductionChapter 1. An Institution in Crisis: the Papal Monarchy on the Eve of Pius’s PontificateChapter 2. The Conciliar Crisis in the Career of Aeneas Silvius Piccolomini and the Pontificate of Pope Pius IIChapter 3. Papal Sovereignty and the Challenge of the Princes: the Experience of Aeneas and PiusChapter 4. Pius II and the Triumph over Conciliarism: A New Reading of the CommentariesChapter 5. The Triumph over the Princes and the Triumph of a PrinceChapter 6. Portraits of Princes in the Portrait of Pius IIConclusion

‘This is a valuable study that serves to remind us of the importance of deep context and a thorough examination of historical evidence, not only in studying the papacy, but throughout the discipline.’- Jennifer Mara DeSilva (Sixteenth Century Studies vol 47:02:2016) ‘We have to give a lot of credit to O’Brien’s efforts to untangle the complex political situation under Pius…. This excellent study concludes with notes, the bibliography, and the most welcome index.’- Albrecht Classen (Mediaevistik vol 29:2016) ‘O’Brien’s book is a fascinating example of humanist history studied through the lens of politics. It is sure to stand at the center of future conversations about Pope Pius II’s Commentaries for years to come.’- Brian Jeffrey Maxson (Renaissance Quarterly vol 70: 01:2017) ‘As a text, The Commentaries of Pope Pius II is one of the richest sources for the studies on fifteenth-century intellectual culture.’- Barry Torch (Renaissance and Reformation vol 40:02:2017) "On the basis of this study, Pius remains a fascinating figure. O’Brien should be congratulated heartily for having rekindled interest in him with such affection, and for having written about him with such clarity."- Miles Pattenden, Australian Catholic University (Recensiones Librorum)