(31 Mar. 1829–30 Nov. 1830)
Born at Cingoli, near Ancona, on 20 Nov. 1761, of noble parentage, Francesco Saverio Castiglione was educated at Osimo, later studying canon law at Bologna and Rome. Having become an expert in the subject, he served the commission investigating the synod of Pistoia (1786) as secretary, was vicar-general to a series of able bishops and then provost of Cingoli, and was himself appointed bishop of Montalto in 1800. He was exiled from his see 1806–14 for refusing to swear allegiance to the Napoleonic regime in Italy. Pius VII created him cardinal priest of Sta Maria in Transpontina and bishop of Cesena, in Emilia, in 1816, and in 1821 called him to Rome to be bishop of Frascati and Grand Penitentiary. The pope, who greatly valued him, hoped he would succeed him, and in fact he just missed being elected in 1823 because he approved of Consalvi's conciliatory policy. At the five-week conclave of 1829 he was the candidate of the moderates, and in spite of serious ill health was elected with the backing of both France and Austria.
Pius aimed at reviving the tradition of Pius VII, whose name he adopted. Not greatly interested in politics, he had a keen concern for pastoral and doctrinal issues. He used his first (and only) encyclical (Traditi humilitati nostrae: 24 May 1829) to trace the breakdown of religion and the social and political order to indifferentism in matters of faith, the activities of the Protestant Bible Societies, attacks on the sacredness of marriage and church dogmas, and secret societies. In a brief of 25 Mar. 1830 he condemned both the influence of Freemasonry in education and the loose morals of the rising generation. Yet while inflexibly upholding traditional positions, he could on occasion be accommodating. Thus he greatly mitigated the harsh police regime which Leo XII had imposed on the papal states, and introduced a number of intelligent changes in the economic and social spheres. Again, in dealing with the problem of mixed marriages which had arisen in Prussia as a result of its acquisition of the Catholic Rhineland and Westphalia in 1815, he reaffirmed that such marriages could only receive the church's blessing if guarantees of the children's education in the Catholic faith were provided, but if they were not he was prepared to permit the priest to be present in a passive role. The government, which supported the German rule that the father's wishes should prevail, was not satisfied, and the conflict was to break out afresh in the following pontificate.
Pius delegated foreign affairs in the main to the openly pro-Austrian cardinal Giuseppe Albani, who had brought about his election and whom he at once appointed secretary of state. As a result his policy towards the dioceses of Latin America formerly subject to the Spanish crown was less progressive than that of Leo XII and reactionary compared with that of his successor. Under Albani the curia adopted a hostile attitude to the movements of national emancipation which broke out in Belgium, Ireland, and Poland in 1830; Albani stigmatized the alliance of Catholics and liberals in Belgium against King William I (1815–40) as ‘monstrous’. On the other hand, against the advice of the curia and his own nuncio, Pius soon accepted the July Revolution (1830) in Paris which deposed the unpopular King Charles X (1824–30) in favour of Louis-Philippe, king of the French (1830–48). When some legitimist bishops and priests fled from France, he showed his disapproval by refusing them admission to the papal states, urging them instead to stay at their posts. In view of the new regime's promise to respect the concordat of 1801, he called on the French clergy to rally to it, and insisted on bestowing the traditional title of ‘Most Christian King’ on Louis-Philippe.