Son of Marcello Lambertini and Lucretia Bulgarini.
Received his early education from tutors.
At age thirteen he went to the Collegium Clementianum in Rome to study rhetoric, philosophy, theology, history, civil and ecclesiastical law.
Received his doctorate in theology, canon law and civil law from La Sapienza University, Rome on 11 September1694 at the age 19.
Made consistorial lawyer by Pope Clement XI.
Consultor of the Supreme Sacred Congregation of the Roman and Universal Inquisition.
Named Promotor of the Faith in 1708.
Canon theologian at the Vatican, and assessor of the Sacred Congregation of Rites in 1712.
Papal domestic prelate in 1713.
Sub-deacon on 17 April1713.
Secretary of the Sacred Congregation of the Council in 1718.
Canonist of the Apostolic Penitentiary in 1722.
Titular Bishop of Theodosia on 12 June1724.
Titular archbishop of Mira.
Titular archbishop of Nazianzo.
Named assistant at the Pontifical Throne on 13 March1725.
Bishop of Ancona on 20 January1727.
Created cardinal on 9 December1726.
Part of the conclave of 1730 that chose PopeClement XII.
Archbishop of Bologna on 30 April1731.
Chosen 247th pope in 1740.
His pontificate coincided with a period when Europeans were turning against the Church, and the prestige of the Holy See was in decline.
Ruled that the baptism of the children of Jews or pagans without the consent of their parents was valid but illicit, as it would be dangerous to baptize children who might lose their faith when they reached the age of reason; when a Jewish or pagan child was baptised without parental consent, the children should be taken away from their parents to be raised in a devout religious manner.
Involuntary adult baptism was declared invalid.
Forcible baptism of Jews was forbidden.
Declared that it was sinful to make a profit from lending money.
Approved the founding of the Passionists and Redemptorists.
Condemned Freemasonry and the works of Voltaire.
Investigated whether the Jesuits were moving beyond Papal control.