In 1560–1 Pope Pius iv (1559–65) instigated a series of trials against the nephews of his predecessor, the austere and unpopular Paul iv (1555–9), as well as other senior clerics, for assorted acts of theft, corruption, murder and abuse of power. The trials, conducted before the court of the Governor of Rome, were the only occasion in the sixteenth century when members of a papal family were successfully impeached, and led to the execution of Cardinal Carlo Carafa and his brother Giovanni, the duke of Paliano, and the disgrace of the youthful Cardinal Alfonso Carafa among others. The Carafa nephews have long been depicted as self-serving, hypocritical and vice-ridden, and their fall has been taken to mark the transformation of papal nepotism from a ‘political nepotism,’ focused on building a family state, to the ‘bourgeois’ motive of amassing a family fortune. Miles Pattenden has sifted through the records of the trials and an array of other documents to argue that the trials were the result not so much of the manifest corruption of the Carafa nephews as of the desire of Pius iv to assert his authority as pope and to dominate the college of cardinals in the days leading up to the final sessions of the Council of Trent. The contrast between the politically shrewd and calculating Pius iv, ever attentive to the need to fend off opposition and to forge alliances with forces inside and outside of Italy, and the political isolation and lack of foresight of the Carafa, which began with the elderly Paul iv himself, determined the progress and outcome of the trial. This study, based on thorough research in Vatican, Italian and Spanish archives and supported by abundant documentation, provides invaluable insight into the workings of the papal court and the personality of Pius iv, who is often glossed over as a ‘faceless bureaucrat’. It also challenges the theory that Pius' pontificate witnessed a deep change in the practice of nepotism at the papal court, emphasising that Pius’ activity was based on self-interest and practicality rather than a reforming idealism. The narrative continues through to later steps taken by Pope Pius v (1566–72) to reverse the verdict of 1561 and to restore the fortunes of the surviving members of the Carafa family. Pattenden's book is a fascinating study and an invaluable addition to our knowledge of the papacy in the era of the Catholic or Counter-Reformation.