The case of Jean Calas, the subject of another of Voltaire's campaigns, had shown that legal authorities were fully prepared to ignore basic principles of law and justice in acting against members of the minority religion.
On 9 October 1760, Elizabeth suffered such a mental breakdown as a result of the ill treatment she received from the Dames Noires that they released her.
Initially medical examinations found that she had suffered no violence but, under pressure from the public prosecutor Trinquier of Mazamet, they changed their evidence to say that Elizabeth had not died by drowning.
A sentence passed on them in absentia on 29 March 1764 condemned the father to be broken on the wheel, the mother to be hanged and the two surviving daughters to be banished.
Étienne Noël Damilaville (1723-1768) was a valuable ally of Voltaire and the philosophes: as a clerk in the revenue service (Bureau du Vingtième) he could use the minister's seal on correspondence, ensuring its immunity from censorship.
He despatched the pamphlet, along with a published version of a letter of his to Damilaville of 1 March 1765, to influential figures in France and abroad, to build the pressure on the authorities to act.
It still took until 23 January 1768 to persuade the Conseil du Roi (Royal Council) to consider the case, and Sirven's plea was rejected.
Il a purgé la mémoire de feue mon épouse et nous a relaxés de l'indigne accusation imaginée par les fanatiques Castrois, m'a accordé la main levée des biens et effets saisis, avec restitution des fruits, et m'a accordé les dépens.
[…] Votre nom Monsieur, et l'intérêt que vous preniés à ma cause ont été d'un grand poids.