Stefano Infessura (Rome, ca 1435- ca 1500), an antipapal humanist lawyer is remembered through his Diary of the City of Rome, a gossipy chronicle of events at Rome. He was in a position to hear everything that circulated in informed and partisan Roman circles, for he was the longtime secretary of the Roman Senate. Anecdotes that Infessura relates may be colored by his own partisan nature, but his diary faithfully records news that was making the rounds in the city.

Infessura's diary, partly in Latin and partly in Italian, the Diarium urbis Romae (Diario della Città di Roma) is of special firsthand value for the pontificates of Paul II (1484-1492), Sixtus IV (1471-84), Innocent VIII (1484-1492), and the beginning of Alexander VI's pontificate.

Infessura took a degree of Doctor of Laws and served as a judge, before he came to the University at Rome as professor of Roman law. "Under Sixtus IV, his office was affected by the financial measures of that pope, who frequently withheld the income of the Roman University, applied it to other uses, and reduced the salaries of the professors" the Catholic Encyclopedia relates. That may not provide adequate motivation for Infessura's deep opposition to Sixtus' policies, and for anecdotes that would be certainly scurrilous if they are untrue. He was not the only contemporary Roman who noted Sixtus' predilection for young boys, not utterly unheard of in other ages, which so shocked the Catholic historian of the Papacy, Ludwig Pastor, a hundred years ago.

Infessura became entangled in the conspiracy of Stefano Porcaro against Nicholas V (1453), which aimed at overturning the papal secular powers in Rome and the Papal States and reviving the Roman republic of antiquity (cf Cola di Rienzi, perhaps a defensible ambition to a modern reader. Among the paganizing Humanists of the Roman Academy under Pomponio Leto, Infessura certainly belonged to the antipapal faction. (L. Pastor, Geschichte der Päpste, 1901-6, i, 550ff; ii, 322ff).

The Catholic Encyclopedia warns

The antipapal and republican temper of the author, also his partisan devotion to the Colonna, and his personal animosity, led him to indulge in very severe charges and violent acusations of the popes, especially Sixtus IV. He put down in his chronicle every fragment of the most preposterous and malevent gossip current in Roman society; even obvious falsehoods attributed to him. He is therefore not considered a reliable chronicler. It is only with the greatest caution and after very careful criticism that his work can be used for the papal history of his time."

Papst and other Catholic authors take pains to discredit the story of Innocent VIII's deathbed. As the Pope sank into a coma, "the harrowing story was told that, at the suggestion of a Jewish physician, the blood of three boys was infused into the dying pontiff’s veins. They were ten years old, and had been promised a ducat each. All three died." Historians of medicine note this event as the first recorded historical attempt at a blood transfusion.

The 'Diarium' was first edited by J. G. Eckhardt, Corpus historicum medii aevi Leipzig, 1723, ii, 1863-2016); afterwards, with omission of the most scandalous parts by L. A.Muratori (Scriptores rerum Italicarum, III, ii, 1111-1252). The critical edition of the text is Tommasini, Diario della Città di Roma di Stefano Infessura scribasenato in the series Fonti per la storia d'Italia, vi, Rome, 1890).