Pierre du Calvet (1735 – March 28, 1786) was a Montreal trader, justice of the peace, political prisoner and epistle writer of French Huguenot origin.

[1] Pierre du Calvet was born in the Summer of 1735 in Caussade in the French province of Guyenne (today the Tarn-et-Garonne département).

In the main epistle of his Appel à la Justice de l'État, he quotes long excerpts from Pufendorf, Gratian, Grotius, Locke and Machiavelli.

Du Calvet thus embarked for Quebec City on board the merchant ship Le Lion, which left Bordeaux in April 1758.

In the summer of 1759, he took part to a mission to transfer British war prisoners to Halifax under officer Jean-François Bourdon de Dombourg.

He was again charged with a mission in Acadia, this time to perform a population census on the Acadians and determine ways to provide assistance to them.

Upon his return, he was almost immediately sent to Sainte-Foy for the last important battle between the French and British Armies before the capitulation and surrender of Montreal on September 8.

In Paris, he landed with letters of introductions for Francis Seymour-Conway, 1st Marquess of Hertford, the British Ambassador to France and his secretary, David Hume, the already famous philosopher, who both interceded in his favour before the Comte de Saint-Florentin.

Du Calvet seemed to have put a great zeal in the exercise of his public duties and was soon praised by the Chief Justice the province, William Hey.

In 1769, he submitted a reform plan to the new governor Guy Carleton which aimed for the uniformisation of the administration of justice in the province of Quebec.

He however was placed at odds with a few fellow-members in the magistracy, including his neighbour John Fraser, as well as Edward Southouse and René-Ovide Hertel de Rouville.

John Fraser, captain of 60th British Royal Regiment, became Justice of the Peace in 1765, shortly after being released, for lack of evidence, in a case of violence involving him and merchant Thomas Walker, friend of du Calvet, who on September 6, 1764, lost an ear during an assault on his person.

On October 26, the first Continental Congress addressed a letter to the inhabitants of the province in which the form of government given to the people by the Quebec Act was severely criticized.

The people were invited to give themselves the provincial representation the Quebec Act did not provide for, and have this representative body send delegates to the upcoming continental Congress, to be held in Philadelphia on May 10, 1775.

In the climate of high suspicion that precedes the entry of the Congress's army on the territory of the province of Quebec, many citizens were arrested and among them was du Calvet.

Joseph Simon Léonard, officer of militia at Pointe-aux-Trembles, accused du Calvet of collaboration with the "rebels".

Du Calvet was part of a committee of citizens who greeted the representatives of the Continental Congress with an address, written by Valentin Jautard on November 14.

Pierre du Calvet continued his public denunciation of the administration of justice by publishing open letters in it.

On December 6, 1780, a little over a month after his arrest, governor Haldimand accepted the request for the release of du Calvet which legislative councillor François Lévesque had submitted him.

Out of prison, du Calvet left the continent for London where he intended to put governor Haldimand to trial for violating the British constitution.

Not conversant in the English language, he received the help of Francis Maseres and Petier Livius to write the document, which contains a detailed account of his confrontation with judge Fraser, his arrest, sequestration, his numerous letters asking to be trialled before a jury of his peers, etc.

He undoubtedly contributed to the involvement of citizens, French-speaking and English-speaking, Catholic and Protestant, in a common effort to obtain a House of Assembly for the province of Quebec.

Indeed, a few months after the probable arrival of the first copies of his collection of letters, numerous persons were signing the Petition of Ancient and New Subjects for a House of Assembly dated November 24, 1784.

Éva Circé-Côté dedicated chapter V of her book Papineau - Son influence sur la pensée canadienne to "the one who inaugurated the most glorious period of our annals".