The History of the Popes (Vol. IV) : From the Close of the Middle Ages examines the pontificate of Pope Paul II and the early years of Pope Sisto IV. It focuses on the dynamics of Renaissance Rome. This volume specifically examines Pope Paul II, highlighting his reign against the humanists, his campaign against heresy, and his influence on the politics, art, and architecture of Rome during that period. It also details Pope Sisto IV from the beginning of his pontificate to his struggles with the political conflict with Venice. It also includes a detailed account of the Vatican's secret archives, compiled based on a thorough investigation of the Vatican's secret archives and various original documents. This comprehensive work encompasses 40 volumes covering 56 popes.