Prospero Lorenzo Lambertini, born into a noble family of Bologna, at this time the second largest city in the Papal States, had been created Cardinal-Priest of Santa Croce in Gerusalemme on May 10, 1728 and had been elected Pope in 1740 to succeed Clement XII.

The conclave that elected him had lasted for six months, and he is reported to have said to the cardinals: "If you wish to elect a saint, choose Gotti; a statesman, Aldrovandi; an honest man, me".

His pontificate had begun in a time of great difficulties, chiefly caused by the disputes between Catholic rulers and the Papacy about governmental demands to nominate bishops rather than leaving the appointment to the Church.

He has managed to overcome most of these problems—the Holy See's disputes with the Kingdom of Naples, Sardinia, Spain, Venice, and Austria are settled.

He will have a very active papacy, reforming the education of priests, the calendar of feasts of the Church, and many papal institutions.

Perhaps the most important act of Benedict XIV's pontificate is the promulgation of his famous laws about missions in the two bulls, Ex quo singulari and Omnium solicitudinum.

In these bulls, he rules on the custom of accommodating Christian words and usages to express non-Christian ideas and practices of the native cultures, which had been extensively done by the Jesuits in their Indian and Chinese missions.

An example of this is the statues of ancestors—there had long been uncertainty whether honor paid to one's ancestors was unacceptable 'ancestor worship,' or if it was something more like the Catholic veneration of the saints.

This question is especially pressing in the case of an ancestor known not to have been a Christian.

The choice of a Chinese translation for the name of God had also been debated since the early seventeenth century.

Benedict XIV denounces these practices in these two bulls.

The consequence of this is that many of these converts leave the Church.

Benedict XIV on December 22, 1741, promulgates the papal bull "Immensa Pastorum principis" against the enslavement of the indigenous peoples of the Americas and other countries.

Pope Benedict XIV has improved the finances of the Papal States, reduced taxes, encouraged agriculture and free trade and drastically cut the military budget, but has been unable to completely reform the administration, still corrupt from previous papacies.

At the University of Bologna he has revived the practice of anatomical studies and established a chair of surgery.

He has a clear view of ecclesiastical problems, has respect for differing opinions and an ability to distinguish between dogma and theory.
 
Benedict's health worsens in 1758 and after a battle with gout, he dies on May 3, 1758 at the age of eighty-three.

His final words to those surrounding him on his deathbed are, "I leave you in the hands of God."

Following his funeral, he is interred in Saint Peter's Basilica and a large catafalque will be erected in his honor.

Benedict had commissioned a team of architects led by Nicola Salvi and Luigi Vanvitelli to design a large palace that is to be 'more complex and with greater baroque style than the box of a palace Vanvitelli designed in Caserta'.

The palace was to be built south of St. Peter's Basilica, but will never be built, as the plans will be quietly ignored by Benedict's successor, Clement XIII.

They will be brought up once more by Pius VI late in his papacy, but will be stopped due to the possibility of invasion.

Carlo della Torre di Rezzonico, the future Clement XIII, was born in 1693 to a recently ennobled family of Venice, the second of two children of the man who bought the unfinished palace on the Grand Canal (now Ca' Rezzonico) and finished its construction.

Born to Giovanni Battista Rezzonico and Vittoria Barbarigo, his brother is Aurelio.

He had received a Jesuit education in Bologna and later studied at the University of Padua where he obtained his doctorate in canon law and civil law.

From there, he had traveled to Rome, where he attended the Pontifical Academy of Ecclesiastical Nobles.

Rezzonico became the Referendary of the Apostolic Signatura and remained in that position from 1716 to 1718 when he was appointed as the Governor of Fano.

He was then ordained to the priesthood on December 23, 1731 in Rome.

Pope Clement XII appointed him to the cardinalate in 1737 as the Cardinal-Deacon of San Nicola in Carcere; Rezzonico had also filled various important posts in the Roman Curia.

Rezzonico had been chosen as Bishop of Padua in 1743 and received episcopal consecration in Rome by Pope Benedict XIV himself.

Rezzonico had visited his diocese on frequent occasions and reformed the way that the diocese ran, paying attention to the social needs of the diocese; he had been the first to do this in five decades.

He later opted to become the Cardinal-Priest of Santa Maria in Aracoeli in 1747 and later to become the Cardinal-Priest of San Marco in 1755.

The College of Cardinals gathered at the papal conclave in order to elect a successor to Benedict XIIV after his death from gout.

Direct negotiations between the rival factions had resulted in the proposal for the election of Rezzonico.

On the evening of July 6, 1758, Rezzonico had received thirty-one votes out of a possible forty-four, one more than the required amount.

He selects the pontifical name of "Clement XIII" in honor of Pope Clement XII, who had elevated him to the cardinalate.

Rezzonico is crowned as pontiff on July 16, 1758 by the protodeacon, Cardinal Alessandro Albani.

In the same year, the Rezzonico family will celebrate Ludovico Rezzonico's marriage into the powerful Savorgnan family.

Rezzonico will be notorious for his rampant nepotism throughout his pontificate.

Clement XIII's pontificate will be repeatedly disturbed by disputes respecting the pressures to suppress the Jesuits coming from the progressive Enlightenment circles of the philosophes in France.

Clement XIII places the Encyclopédie of D'Alembert and Diderot on the Index Librorum Prohibitorum, but this index is not as effective as it had been in the previous century.

More unexpected resistance comes from the less progressive courts of Spain, the Two Sicilies, and Portugal.

The reforming minister of Joseph I of Portugal, the future Marquis of Pombal, expels the Jesuits from Portugal in 1759 and transports them all to Civitavecchia, as a "gift for the Pope."