[3] With his doctorate in law, Caprara was appointed in 1755 referendary of the Tribunals of the Apostolic Signature; from 1758 to 1761 he served as vice-legate of the papal state of the Romandiola, with its capital at Ravenna.

In 1772 he visited the Netherlands and was sent by Pope Clement XIV as his personal agent to the United Kingdom, where he was presented to King George III by the Austrian ambassador.

When Caprara's mission became a matter of public knowledge, Pope Clement was denounced in various cities as a heretic, and anti-Catholic sentiment in England was aroused to the point that the British government severed its contacts with the Papacy.

[8] Due to health problems (the official reason, but actually at the request of the Empress Maria Theresa), on 6 September 1775 Caprara was appointed nuncio at Lucerne.

The papal Secretary of State (prime minister), Cardinal Francesco Saverio de Zelada (1789–1796), was dissatisfied with his conduct in Vienna.

Caprara, with his compliant and passive nature, did not oppose the religious reforms undertaken by Joseph II, who was attempting to make the Catholic Church in his empire the tool of the state, and independent of the papacy.

[10] In order to end his tenure of the nunciature in Vienna in an honorable way, on 18 June 1792 Caprara was promoted Cardinal Priest by Pope Pius VI, with the titular church of Sant'Onofrio in Rome.

Hrzan replied that the Legations had been detached from the Papal States by a solemn treaty which had been signed by the Pope, and that they had been conquered by Austrian troops from the Cisalpine Republic.

[19] After the Conclave, Caprara requested that Hrzan use his influence with the Austrian government to see to it that his income from his benefice at S. Maria della Grazie in Bologna was paid.

[24] At the end of June 1800, however, Cardinal Bussi de Pretis, Bishop of Jesi, died, and it immediately became the gossip of the Papal Court en route that Caprara was being considered as his successor.

This presented grave spiritual and canonical problems for Pius VII, since the bishops were heretics and schismatics, and it would be impossible to appoint them to diocesan posts without a full confession of guilt, as well as retractation of their oaths to the Civil Constitution of the Clergy and submission to the judgment of the Pope.

[33] During the negotiations which followed concerning the execution of the Concordat of 1801, Caprara displayed a conciliatory spirit in dealing with the ten constitutional bishops who were to be appointed, at least according to Bonaparte's demand, to as many of the newly established dioceses; in fact, Caprara went contrary to specific instructions from Cardinal Consalvi in Rome, under persistent pressure exerted by Napoleon.

[35] Cardinal Caprara officiated at the Solemn restoration of public worship in Paris at the cathedral of Notre-Dame on Easter Day (18 April 1802), at which function the First Consul, the high officers of state, and the new ecclesiastical dignitaries assisted.

After the reading of the gospel of the day, twenty-seven bishops who were present knelt at the feet of Bonaparte and took a solemn oath of allegiance to the government and the French Republic.

[38] In a letter of 18 August 1803, Caprara, too, protested against the Organic Articles for "establishing in France an ecclesiastical code without the cooperation of the Holy See....

The Church has received from God alone the authorization to decide questions of the doctrine of the faith or of the regulation of morals, and to make canons or rules of discipline."

[41] During the absence of Caprara from Milan, the diocese was ruled by the Vicar general, Carlo Bianchi, who had to deal with the anticlerical measures of the Kingdom of Italy, such as the imposition of an oath to the state Secretary of Cults to be taken by seminary professors, and the compulsory abolition of most confraternities.

Among other things, Lesson 7 of Part I of the document mentioned Napoleon I by name and urged the faithful to do their duty to him, "firstly, because God... plentifully bestowing gifts upon our Emperor, whether for peace or for war, has made him the minister of his power, and his image upon earth....

Relations between Napoleon and the Papal States became more and more difficult, especially with the implementation of the continental blockade against England, in which Pius VII refused to participate or to sanction.

Caprara's desire to please Napoleon lead to increasing dissatisfaction on the part of the Pope and the Secretary of State Cardinal Ercole Consalvi.

[43] The situation degenerated in 1808 when the Napoleonic army entered the Papal States on 3 February 1808, and General Miollis occupied Rome.

In April 1808, Cardinal Caprara was ordered by Pius VII to demand his passports, that is to say, to quit his position as Legate and leave France.

By order of Napoleon, Caprara was given a solemn funeral and his body was entombed in the Panthéon of Paris (Crypt III), while his heart was buried in Milan Cathedral.