Horace K. Mann
A priest, educator, and historian, Mann dedicated his scholarly life to the medieval papacy, emerging as the preeminent English historian in this field during the 20th century. His monumental work chronicling the lives of popes through the early Middle Ages remains a valuable, though largely superseded, resource. Mann also authored independent biographies and contributed significantly to scholarly encyclopedias and journals, solidifying his legacy in the study of papal history.