This book contains a study of twenty famous Popes whose careers and whose influence were important in the development of the church and in the history of the world. Contents: St. Callistus and the Early Struggle; St. Damasus and the Triumph; Leo the Great, the Last Pope of Imperial Rome; Gregory the Great, the First Medieval Pope; Hadrian I and the Temporal Power; Nicholas I and the False Decretals; John X and the Iron Century; Hildebrand; Innocent III, the Papal Zenith; John XXII, the Court at Avignon; John XXIII and the Great Schism; Alexander VI, the Borgia-Pope; Julius II, the Fighting Pope; Leo X and the Dance of Death; Paul III and the Counter-Reformation; Sixtus V and the New Church; Benedict XIV, the Scholar Pope; Pius VII and the Revolution; Pius IX; Leo XIII.