David I. Kertzer is the author of The Pope Who Would be King: Pius IX and the Emergence of Modern Europe. His book The Pope and Mussolini won the Pulitzer Prize for Biography in 2015, and his book The Kidnapping of Edgardo Mortara was a finalist for the National Book Award for Nonfiction in 1997. He is the Dupee University Professor of Social Science at Brown University.