Born at the Castello della Genga in the territory of Spoleto, 22 August, 1760; died in Rome, 10 February, 1829. His father's family had been ennobled by Leo XI in 1605; his mother was Maria Luisa Periberti of Fabriano. They had a large family, seven sons and three daughters, of which Annibale was the fifth son and sixth child. At the age of thirteen he was placed in the Collegio Campana of Osimo, whence he was transferred, in 1778, to the Collegio Piceno in Rome and shortly afterwards to the Accademia dei Nobili Ecclesiastici. He was ordained subdeacon four years later, and deacon in 1783. Two months later he was ordained priest, dispensation being obtained for the defect of age, as he was only twenty-three. He was of handsome person and engaging manners and, soon after his ordination, attracted the notice of Pius VII, who was visiting the Accademia, and by him was raised to the prelature as cameriere segreto. In 1790 he was chosen to deliver in the Sixtine Chapel the oration on the death of the Emperor Joseph II and accomplished his difficult task to the admiration of all hearers, without offending the susceptibilities of Austria or compromising the authority of the Holy See. In 1792 he became a canon of the Vatican church, and the following year was consecrated titular Archbishop of Tyre and sent as nuncio to Lucerne. Thence he was transferred to the nunciature at Cologne in 1794, a post which he occupied with great success for eleven years. In 1895 he was accredited as nuncio extraordinary to the Diet of Ratisbon by Pius VII in order that he might deal with the difficulties between the German Church and its Prussian rulers. Returning to Rome to confer with Consalvi on these matters, he learnt that Napoleon desired the substitution of another nuncio more devoted to his interests, in the person of Bernier, Bishop of Orléans. Pius VII, however, was firm and Della Genga returned to Munich. In 1798 he went with Cardinal Caprara to Paris with the object of arranging some agreement between the Holy See and Napoleon I. He was received, however, but coldly, and the negotiations soon came to nothing. Della Genga returned to Rome where he witnessed the indignities offered to Pius VII by the French. He returned in dismay to the Abbey of Monticelli, which had been granted to him in commendam for life by Pope Pius VI. Here he spent his time teaching his choir of peasants to play the organ and to sing plain-chant.

Expecting to end his days there, he built in the abbey church the tombs of his mother and himself. But in 1814, with the fall of Napoleon, Pius VII returned to Rome and Mgr Della Genga was sent to Paris as envoy extraordinary to convey the pope's congratulations to King Louis XVIII. Consalvi, however, who was accredited to all the sovereigns then at Paris, strongly resented this mission, which he held to be a slight to himself. Louis XVIII endeavoured to smooth over matters, but the powerful Secretary of State had his way, and Della Genga returned to Rome, whence he again retired to Monticelli. Here he remained for two years, when Pius VII created him cardinal of Santa Maria in Trastevere and appointed him Bishop of Sinigaglia. But his ill-health necessitated residence in the healthy air of Spoleto and he never entered his diocese, which he resigned two years later. In 1820, his health being improved, he was made Vicar of Rome, arch-priest of the Liberian Basilica and prefect of several congregations. Three years later, on 20 August, Pius VII died; and on 2 September the conclave opened at the Quirinal. It lasted for twenty-six days. At first the most prominent candidates were Cardinal Severoli, the representative of the Zelanti, and Cardinal Castiglioni (afterwards Pius VIII), the representative of the moderate party. Castiglioni was the candidate most desired by the great Catholic powers, but, in spite of their wishes Severoli's influence grew daily and by the morning of 21 September, he had received as many as twenty-six votes. As this meant that he would probably be elected at the next scrutiny, Cardinal Albani, who represented Austria at the conclave, informed his colleagues that the election of Cardinal Severoli would not be acceptable to the emperor and pronounced a formal veto. The Zelanti were furious, but, at Severoli's suggestion, transferred their support to Della Genga, and before the powers realized what was happening, triumphantly elected him by thirty-four votes on the morning of 28 September. At first, however, the pope-elect was unwilling to accept the office. With tears he reminded the cardinals of his ill-health. "You are electing a dead man", he said, but, when they insisted that it was his duty to accept, he gave way and gracefully assuring Cardinal Castiglioni that he some day was to be Pius VIII, announced his own intention of taking the style of Leo XII.

Immediately after his election he appointed Della Somaglia, an octogenarian, Secretary of State, an act significant of the policy of the new reign. Leo was crowned on 5 October. His first measures were some not very successful attempts to repress the brigandage and license then prevalent in Maritima and the Campagna, and the publication of an ordinance that confined again to their Ghettoes the Jews, who had moved into the city during the period of the Revolution. These measures are typical of the temper and policy of Leo XII. There is something pathetic in the contrast between the intelligence and masterly energy displayed by him as ruler of the Church and the inefficiency of his policy as ruler of the Papal States. In face of the new social and political order, he undertook the defence of ancient custom and accepted institutions; he had little insight into the hopes and visions of those who were then pioneers of the greater liberty that had become inevitable. Stern attempts were made to purify the Curia and to control the crowd of inefficient and venal officials that composed its staff. Indifferentism and the Protestant proselytism of the period were combated; the devotion of the Catholic world was estimated by the jubilee of 1825, in spite of the opposition of timid and reactionary prelates or sovereigns; the persecution of the Catholics in the Netherlands was met and overcome, and the movement for the emancipation of the Catholics in the British Isles was managed and encouraged till success was assured. Popular discontent with the government of the Papal States was met by the severities of Cardinal Rivarola.

The legitimist cause in France and in Spain, though marked in both countries by the misuse of religion as an instrument of political reaction, was supported, even when (as in the suppression of the Jesuit schools in France, and the vacancy of Mexican sees owing to the claims of Spain over her former colonies) the representatives of that cause showed themselves indifferent or opposed to the interests of the Faith. Consalvi was consulted and admired by the pope, who, both in this case and that of the treasurer Cristaldi, showed himself too magnanimous to allow personal grievances to weigh against the appreciation of merit, but the cardinal's death in 1824 prevented the contribution of his wisdom to the councils of the Holy See. The Collegio Romano was restored to the efficient hands of the Jesuits in 1824; the Free-masons and other secret societies were condemned in 1825; the Vatican printing press was restored and the Vatican Library enriched; scholars like Zurla, Martucci, and Champollion were encouraged; much was done towards the rebuilding of St. Paul's and the restoration of the seemliness of worship. But Leo's health was too frail to support his unremitting devotion to the affairs of the Church. Even in December, 1823, he had nearly died, and recovered only as by a miracle, through the prayers of the venerable Bishop of Marittima, Vincenzo Strambi, whose life was offered to God and accepted in the stead of the pope's. On 5 February, 1829, after a private audience with Cardinal Bernetti, who had replaced Somaglia as Secretary of State in 1828, he was suddenly taken ill and seemed himself to know that his end was near. On the eighth he asked for and received the Viaticum and was anointed. On the evening of the ninth he lapsed into unconsciousness and on the morning of the tenth he died. He had a noble character, a passion for order and efficiency, but he lacked insight into, and sympathy with, the temporal developments of his period. His rule was unpopular in Rome and in the Papal States, and by various measures of his reign he diminished greatly for his successors their chances of solving the new problems that confronted them.

ARTAUD DE MONTOR,Histoire du Pape Léon XII (Paris, 1843); CHATEAU7BRIAND,Mémoires d'outre-tombe, II (Brussels, 1892), 149-202; XXXVIII, 50-83; WISEMAN,Recollections of the Last Four Popes (London, 1858), 209-352.

Non-Catholic: BENRATH in HERZOG AND HAUCK,Real-encyclopädie, XI (Leipzig, 1902), 390-393; NIELSEN,History of the Papacy in the XIXth Century, II (London, 1906), 1-30.

Leslie A. St. L. Toke