Days after the assassination of his prime minister in the middle of Rome in November 1848, Pope Pius IX found himself a virtual prisoner in his own palace. The wave of revolution that had swept through Europe now seemed poised to put an end to the popes' thousand-year reign over the Papal States, if not indeed to the papacy itself. Disguising himself as a simple parish priest, Pius escaped through a back door. Climbing inside the Bavarian ambassador's carriage, he embarked on a journey into a fateful exile. Only two years earlier Pius's election had triggered a wave of optimism across Italy. After the repressive reign of the dour Pope Gregory XVI, Italians saw the youthful, benevolent new pope as the man who would at last bring the Papal States into modern times and help create a new, unified Italian nation. But Pius found himself caught between a desire to please his subjects and a fear—stoked by the cardinals—that heeding the people's pleas would destroy the church. The resulting drama—with a colorful cast of characters, from Louis Napoleon and his rabble-rousing cousin Charles Bonaparte to Garibaldi, Tocqueville, and Metternich—was rife with treachery, tragedy, and international power politics. David Kertzer is one of the world's foremost experts on the history of Italy and the Vatican, and has a rare ability to bring history vividly to life. With a combination of gripping, cinematic storytelling, and keen historical analysis rooted in an unprecedented richness of archival sources, The Pope Who Would Be King sheds fascinating new light on the end of rule by divine right in the west and the emergence of modern Europe.