The History of the Popes (Vol. XVII) : From the Close of the Middle Ages presents a study of the era of Pope Pius V (1566–1572). This volume provides an in-depth examination of the pivotal period surrounding the Council of Trent, the internal reform of the Catholic Church, and papal efforts to navigate European political conflicts. The author details the conclave process that led to the election of Pope Pius V, as well as his background and character prior to assuming the papacy. The discussion proceeds to cover concrete efforts to implement the decrees of the Council of Trent, focusing on the reform of the College of Cardinals, the Curia, and the clergy, as well as the renewal of religious orders. It also addresses the active role of the Roman Inquisition in upholding doctrinal purity during the Counter-Reformation, the governance of the Papal States, and Pius V’s views on literature, art, and the threat of Ottoman Empire expansion. This comprehensive work spans a total of 40 volumes chronicling the history of 56 popes.