Giovanni Giacinto Achilli (; c. 1803 – c. 1860) was an Italian Roman Catholic Dominican friar and anti-Jesuit who was discharged from priesthood and imprisoned by the Roman Inquisition after being accused of child sexual abuse or for doctrinal heresy. However, Achilli escaped and subsequently became a fervent evangelist for the Protestant Anglican Communion. He is particularly notable for his activities in England and for launching a successful criminal prosecution against John Henry Newman, who made accusations about Achilli's past, for libel.
Early life as a priest
Achilli was born in Celleno, a village c. 30 km from Viterbo, then part of the Papal States. He joined the Dominican order in 1819 and was ordained a priest in 1825.
In 1833 Achilli obtained the degree of Master of Sacred Theology at the Roman College of St. Thomas, the future Pontifical University of Saint Thomas Aquinas, The Angelicum.
In 1840, for being against the abuses of the Roman Inquisition, Achilli underwent a sequence of disciplinary actions and sanctions, largely arising from allegations by his pro-Inquisition opponents of sexual misconduct including the alleged rape of a 15-year-old girl in Naples.
On 16 June 1841, the Roman Inquisition finally lost patience and permanently suspended Achilli from the cure of souls, sentencing him to three years' penance at a remote monastery at San Nazzaro. However, in 1842, Achilli made his way to Corfu, then a British protectorate, and claimed political asylum alleging that he was a cavaliere and that he had escaped from the fortress at Ancona. The local authorities were minded to grant the papal consul's request for extradition until they discovered that Achilli was claiming to have converted to Protestantism and was engaged in fervent anti-Catholic propaganda, largely under the influence of Isaac Lowndes, the Scottish Presbyterian secretary of the Bible Society. He also made alliances with exiled Italian nationalists.
Malta and England
After establishing himself in Malta in 1846, opening an Italian Protestant church, in May 1847 he travelled to London. There, the committee of the Protestant College of St Julian's, Malta, appointed him professor with a special mission to spread Protestantism in Italy. However, during his absence from Malta, two of his fellow Protestant preachers were accused of "fornication" and it was further alleged that Achilli had encouraged them in their misconduct. Achilli returned to Malta in December but was dismissed by the London committee, along with his fellow accused, in May 1848.
However, he returned to London in June, where he still enjoyed important supporters including Sir Culling Eardley Eardley, chairman of the Evangelical Alliance.
Risorgimento
Following the revolutions of 1848 in the Italian states, Rome was in the hands of Italian nationalists who established the Roman Republic in February 1849. Achilli travelled there in early 1849 and continued his Protestant, anti-Catholic and pro-nationalist propaganda. On 24 June 1849 he married Josephine Hely, the youngest daughter of Captain James Hely, whose family he had befriended when in England.
The Roman Republic fell in June 1849 when the French took the city and reinstated Pope Pius IX's political authority. Though French president Louis Napoleon had requested that the Pope grant an amnesty, Achilli was arrested by the Cardinal Vicar and imprisoned by the Inquisition, in the Castel Sant'Angelo, for preaching against the Catholic religion and taking part in revolutionary agitation. There Augustin Theiner attempted to reconvert him to Catholicism, to no avail. Lewis Tonna and other London evangelicals canvassed the French government in October 1849 and succeeding in effecting Achilli's release.
England and controversy
Achilli's evangelical supporters brought him to England and established him in an Italian chapel under the aegis of the Evangelical Alliance. A series of antagonistic pamphlets established itself between Eardley and prominent English Catholic Cardinal Wiseman, by turns defending and attacking Achilli. In the meantime, Achilli was accused of raping or assaulting four of his domestic servants and a further young woman. In 1850, Pius IX re-established the hierarchy of the Catholic Church in England and Wales (see Roman Catholicism in Great Britain:The Catholic Revival in the Nineteenth Century) and excited popular religious divisions. John Henry Newman was minded to repeat Wiseman's allegations, of sexual immorality and that Achilli had misrepresented his expulsion from the Catholic Church, in a lecture but first took legal advice, on 16 July, from his confidant James Hope-Scott for fear of a libel suit.