Recalled from retirement on 23 September1805 to serve as papalnuncio to the Diet of Ratisbon.
With Cardinal Giovanni Battista Caprara he was a negiator between the Vatican and Napoleon Bonaparte in 1808, but the mission failed.
Papalenvoy to King Louis XVIII on 22 July1814.
He then retired to Monticelli abbey for another two years.
Created cardinal-priest on 8 March1816.
Archbishop of Senigallia on 8 March1816, but his health failed and he resigned on 10 September1816.
Prefect of the Sacred Congregation of Ecclesiastical Immunity on 9 May1820.
Vicar general for the city of Rome on 12 May1820.
Archpriest for the Liberian basilica on 10 February1821.
Reluctant 252nd pope in 1823, fearing that his health would not permit him to work.
He took the name Leo XII, and held the throne for over five years.
Reinstated papal civil authority in the Papal States.
Opposed groups that distributed unauthorized Bible editions and translations, and warned against private interpretation.
Opposed indifferentism which advocates the equality of all religions.
Opposed secret societies, especially the ItalianCarbonari.
Tried to strictly rule Rome, which caused great resentment.
Revived the practice of Jubilees.
Approved the Oblates of Mary Immaculate.
Named Saint Peter Damian a Doctor of the Church.
Saint Vincent Strambi was one of his advisors.
Created 25 cardinals in eight consistories.
Born
22 August1760 at Castello della Genga, diocese of Fabriano, Papal States as Annibale Francesco Clemente Melchior Girolamo Nicola della Genga
![[Pope Leo XII]](pope0252.jpg "10kb jpg detail of a drawing of Pope Leo XII; swiped off the Wikipedia web site; please do not write to ask about the image")