The History of the Popes (Vol. XV) : From the Close of the Middle Ages examines the pontificate of Pope Pius IV (Giovanni Angelo Medici) from his election in 1559 to 1565. This volume details the crucial final stages and conclusion of the Council of Trent, as well as the immediate implementation of the Counter-Reformation across Europe. Key themes include diplomacy and alliances (how Pius IV restored strained relations with major Catholic powers such as Spain, France, and the Republic of Venice), church reform (the resumption, acceleration, and successful conclusion of the Council of Trent, which established modern Catholic doctrine and the seminary system), secular architecture (Pope Pius IV’s patronage of the arts, including commissioning Michelangelo to rebuild several churches and construct the Porta Pia in Rome), and the trial of the Carafa family (political and legal actions taken against the nepotism-ridden administration of the previous pope, Paul IV). This comprehensive work spans 40 volumes, chronicling the reigns of 56 popes.