Cardinal

Donghi was created a cardinal-deacon by Pope Urban VIII in the consistory of 13 July 1643, and assigned the Deaconry of San Giorgio in Velabro on 31 August 1644.^[7] Urban died a year later, on 29 July 1644, and Donghi was one of the fifty-seven cardinals^[8] who participated in the papal conclave of 1644. The Conclave opened on 9 August, and resulted in the election of Pope Innocent X on 15 September 1644.^[9] Donghi was openly a part of the Spanish faction of the College of Cardinals.^[10][6]

Thereafter he was named plenipotentiary of Pope Innocent during the Second War of Castro,^[when?]} returned to Lombardy and helped to reach a treaty with the Duchy of Parma. He and Cardinal Alessandro Bichi signed the Peace on 31 March 1644.

On 3 July 1651 Cardinal Donghi was named Legatus in the Romandiola and the Exarchate of Ravenna by Pope Innocent X.^[11] An inscription in Ravenna, dated 1654, commemorates Donghi's providing supplies of grain to the city during a famine.^[12] He was elected Bishop of Ajaccio, Corsica, on 27 November 1651.^[13]

Pope Innocent X died on 7 January 1655. The Conclave to elect his successor opened on 18 January. Donghi was one of sixty-six cardinals who participated in the Conclave of 1655. On 7 April, after much twisting and turning over the candidacies of Cardinals Sacchetti, Carafa and Chigi, the Cardinals elected Fabio Chigi, who chose the throne name Pope Alexander VII.^[14]

On 14 May 1655 Cardinal Donghi was transferred from the Deaconry of San Giorgio in Velabro to the Deaconry of S. Agata.^[15]

On 2 August 1655 Donghi was appointed bishop of Imola.^[16][17] In Imola he conducted a pastoral visitation throughout his diocese, and then, in 1659, held a diocesan synod. He also received Queen Christina of Sweden as she was on her way to Rome.^[18]

On 26 February 1663, Cardinal Donghi was released from his commitment to Imola, and appointed bishop of Ferrara; he held the diocese until his death.^[19]

Pope Alexander died on 22 May 1667. The Conclave to elect his successor began on 2 June. Ultimately sixty-four of the sixty-eight cardinals participated, including Giovanni Stefano Donghi. The likely candidates seemed to be Cardinal Girolamo Farnese (the French supported him, and the Cardinal nephew Chigi was favorable), Scipione d'Elci (the preference of the Grand Duke of Tuscany, to whom Chigi was also favorable), and Giulio Rospigliosi. On 20 June the Conclave elected Giulio Rospigliosi, who became Pope Clement IX.^[20]

On 12 March 1668, Cardinal Rinaldo d'Este accepted promotion to the rank of Cardinal Priest of S. Pudenziana, which automatically made Cardinal Donghi the senior Cardinal-Deacon in the Sacred College (Protodeacon).

Cardinal Giovanni Stefano Donghi died on 26 November 1669^[21] and was buried in the Chapel of the Madonna at the Church of the Gesù in Rome.^[22] There is no monument or inscription.