As a young man, Nardini served in the military, before joining the ecclesiastical estate and traveling to Rome. He became a canon of Ferrara Cathedral, and later General Treasurer of the Marche. During the pontificate of Pope Callixtus III, he was governor of Romagna. Under Pope Pius II, he was a referendary, and later, a protonotary apostolic. He then served as Pius II's nuncio to Germany; the pope wrote to him on July 15, 1459 about the advance of the Ottoman Empire in the Kingdom of Bosnia.
On November 13, 1461, he was elected Archbishop of Milan. He occupied that see until his death. He then served as a nuncio in the Kingdom of Aragon, in which capacity he successfully sought the derogation of a pragmatic sanction that endangered the freedom of the church. In July and August 1464, he accompanied the pope to Ancona.
Following the death of Pope Pius II, he returned to Rome for the papal conclave of 1464 that elected Pope Paul II. During that conclave, the College of Cardinals had agreed that the number of cardinals should be fixed at 24; Archbishop Nardini and Teodoro Lelio, Bishop of Treviso, advised the new pope in September 1464 not to agree to this limitation. Paul II named Nardini nuncio extraordinary to the Kingdom of Naples. From April 1467 to June 1468, he resided in Paris as papal legate to the Kingdom of France. He was present in Rome when Paul II died in July 1471 and the College of Cardinals named him temporary governor of Rome. In the papal conclave of 1471, the College of Cardinals elected Pope Sixtus IV as the new pope.
As cardinal, he built the Palazzo Nardini on the Via del Governo Vecchio, next to the Palazzo Taverna. On June 10, 1476, he accompanied the pope to Viterbo, and later to Foligno, because of an outbreak of bubonic plague in Rome. In 1476, he opted for the titulus of Santa Maria in Trastevere. He was Camerlengo of the Sacred College of Cardinals from January 8, 1481 until January 7, 1482. In 1483, he founded the Collegio Nardini.
|Catholic Church titles|
Giovanni Battista Zeno
|Camerlengo of the Sacred College of Cardinals