The Accolti conspiracy

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The Accolti conspiracy was an alleged plot against the life of Pius IV organized in December 1564 by Benedetto Accolti, the illegitimate son of the cardinal of the same name who had been accused of treason by Paul III.

Accolti, a charismatic and fervently religious man, seems to have been deeply opposed to proposals made by Pius to allow full communion for the laity and to grant clergy the right to marry (policies demanded by the emperor in the hope of reconciling German Protestants back to the Catholic faith).

It was alleged at his trial that Accolti had persuaded a group of co-conspirators – his nephew Pietro Accolti, Count Antonio di Canossa, Taddeo Manfredi, Giangiacomo Pelliccione, and Prospero de’ Pittori – of a revelation he had received that Pius would be succeeded by a better and more orthodox pope and that they should collaborate to remove him.

Accolti’s plan was to present Pius with a petition demanding his abdication and, in the event that it was refused, to assassinate him with a poisoned dagger. This act, to which Accolti believed he had been inspired by God, was to be assisted by Canossa, Manfredi, and Pelliccione while the other two awaited the results in the piazza of St Peter’s.

In the event, though he was granted a papal audience, Accolti was overcome by fear and proved unable to carry out his plan. The conspirators soon fell out amongst themselves, at which point Pelliccione, fearing that one of the others might reveal the plot, decided to save his own life by betraying it to the authorities.

The conspirators, having been rounded up, were either condemned to death or sent to the galleys for life, depending on the degree of their perceived culpability.

With its echoes of the later assassinations of Henry III and Henry IV of France, the Accolti conspiracy may mark an important moment in the history of the Counter-Reformation when the most fanatical Catholics began to turn on the leaders they held responsible for the spread of Protestantism.

Doubts about this interpretation must remain, however, not least because the plot’s discovery seems so well to have suited Pius’ own agenda. In fact, within the previous two years Pius had uncovered two other attempts to assassinate him – the first by an unknown gunman and the second by the surviving friends of the Carafa family (whose principle members Pius had had executed in 1561) – and used both as excuses to restrict access to his person and stifle dissent. Moreover, though Accolti’s apparent motivation had been opposition to Pius’ inclination to appease the Protestants, under interrogation he was made to confess to having visited Geneva and to have read Calvin’s Institutiones and Luther’s incitements to murder the pope.

Pius’ declining health throughout 1565 reduced tensions in Rome and, in the event, neither the conspiracies against him nor his approach towards religious reform came to anything further.


  • Accolti, Benedetto, in DBI, vol. 1 (1960)
  • Elena Bonora, Roma 1564. La congiura contro il papa (Rome: Laterza, 2011)
  • Ludwig von Pastor, History of the Popes, vol. 16, (London: Kegan Paul, Trench, Trübner & Co., 1928), 383-91
  • Peter Plastenbrei, 'Glücksritter und Heilige: Motivstruktur und Täterprofile bei der Accoltiverschwörung gegen Papst Pius IV. im Jahre 1564', Quellen und Forschungen aus italienischen Archiven und Bibliotheken 70 (1990), 441-90.
  • Renzo Ristori, 'Benedetto Accolti. A proposito di un riformato toscano del Cinquecento (Testi e documenti)', Rinascimento. Rivista dell'Istituto Nazionale di Studi sul Rinascimento 13 (1962), 225-312

Article written by Miles Pattenden | © 2013

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