This text investigates the political and ecclesiastical dynamics of the Council of Basle through the primary account of Aeneas Sylvius Piccolomini. The author, who later ascended to the papacy as Pius II, provides a detailed record of the events surrounding the election of the anti-pope Felix V. This critical edition, revised by Denys Hay, serves as a foundational document for understanding the internal conflicts and shifting allegiances within the 15th-century Church.

Scholars and historians regard this volume as a vital primary source for the study of conciliarism and the political history of the papacy. Readers frequently note the academic rigor of the translation and the clarity provided by the editorial revisions of Denys Hay.