Many years ago, I read Giulio Andreotti's La fuga di Pio IX e l'ospitalità dei Borbone, and remember enjoying it immensely. The seven times Italian prime minister narrated Pius ix’s flight from Rome as something of an historical curiosity. Since then, Owen Chadwick, Michael Rapport and Jonathan Sperber have integrated this defining moment within the broader canvas of the revolutions of 1848/49. Despite this, the pope behind these events is little known, and still awaits a proper scholarly biography in English. The task has now become extremely ‘delicate’ since, in the year 2000, the Catholic Church proclaimed Pius ix ‘Blessed’. Indeed, the canonisation process is on-going, and has revived old controversies that many had thought long-buried. The Edgardo Mortara affair casts a dark anti-semitic shadow over this pope and his far from benign legacy. It is much to David Kertzer's credit not only to describe Pius ix’s experience during revolution in unprecedented depth, but to do so with great scholarly insight, analytical acumen and narrative flair.

These pages describe how Giovanni-Maria Mastai Ferretti, who was elected Pius ix in 1846, had not always been the reactionary pope of the ‘Syllabus of Errors’ or ‘papal infallibility’. His early reforms and liberalisations made him the great hope of Italian nationalists just before Europe was plunged in an almost continent-wide revolution in 1848. To his surprise the pope became the symbol of Italian unity and a rallying point for war against Austria. Yet Pius was no mere Italian prince and his position as head of global Catholicism made his position complicated. After flirting with liberalism and reform, the pope found himself propelled forward on the crest of a wave of popular and revolutionary enthusiasm which he was utterly unable to control, let alone harness. His attempts to rein in the growing radicalisation of the population of Rome and the papal states gave rise to one of the most remarkable volte-faces of history. The liberal beloved Pius ix metamorphosed into the wicked reactionary pope-king who tried to hold back the tide of history. Besieged in the Quirinal Palace, the pope made a daring escape attempt, eventually reaching the safety of the great fortress of Gaeta in the kingdom of Naples. Here he appealed to the Catholic powers to retake Rome and re-establish his absolute rule.

This was to have deeply tragic consequences. The short-lived Roman republic of Giuseppe Mazzini and Giuseppe Garibaldi, despite ending in disaster, kept alive the hope for more enlightened government and a better future. After a bloody siege the papal police re-imposed order with unconcealed ruthlessness. As Kertzer eloquently demonstrates, Pius ix learned all the wrong lessons from his exile. He believed concessions had bred revolution, and spent the next three decades of his overly-long pontificate as the foremost enemy of modernity. Yet, as this fine book argues, the genie was well and truly out of the bottle. 1848 challenged the divine right of the papacy and showed that nobody was immune from accountability … not even Christ's Vicar. Grippingly written, page-turning and scholarly, this book is an immense achievement which few can hope to equal. This is a magnificent book; analysis and narrative at their finest.