DECOSTE, JEAN-BAPTISTE (sometimes called Sieur de Letancour), court officer; b. in 1703 in Paris, France, son of Louis Decoste and Catherine Coré; d. 26 Feb. 1778 at Pointe-Claire (Que.).
Nothing is known about Jean-Baptiste Decoste’s arrival in New France. On 18 Aug. 1725, in Montreal, he married Marie-Renée, the under-age daughter of Nicolas Marchand, a tailor. Although he was only 22, he seems to have been sufficiently wealthy for the notary to set the jointure at 6,000 livres. Apparently his principal sources of income were not in the colony, however, since in the marriage contract Nicolas Marchand agreed to lodge the couple in his house once they were wed and to “heat and keep” them for two years. Marchand also gave his daughter a piece of land on Rue Saint-Paul, next to the family home.
Around 1730 Decoste served as captain of the guards of the Domaine d’Occident. In this capacity he worked to prevent fraud in import and export duties on a certain number of products. He also helped his father-in-law, who since September 1727 had been a court officer in the royal jurisdiction of Montreal, acting either as a witness for him or as an appraiser. Because Decoste was also a legal practitioner and attorney, he knew the ways and customs of the lawcourts and judicial procedure. Hence on 22 Nov. 1731 Intendant Hocquart granted him a commission as court officer for the entire royal jurisdiction of Montreal. After passing the investigation into his character, on 3 Jan. 1732 he entered upon his duties. Six months later, on 23 July, he was appointed court crier for the royal jurisdiction of Montreal, with the duty of attending court sittings and seeing that the silence and respect befitting the court room were maintained. He held this office until 1757, when he was replaced by court officer Nicolas-François Robert. In the mean time, on 8 July 1743, Decoste had succeeded Jean-Baptiste Adhémar* as court officer of the Conseil Supérieur for Montreal; in this capacity he had to carry out in the Government of Montreal all the “decrees, judgements, and other acts” emanating from the council. In 1746 François Dumergue came from Quebec to replace him in this post.
Jean-Baptiste Decoste’s eldest son, Jean-Christophe, was to follow him in court service. Born in Montreal on 14 Aug. 1726, he had received early the rudiments of religion and reading from a lay school-teacher, Louis Fourier. His father then introduced him to the work of a court officer, and on 9 Feb. 1751, when he was 24, he was appointed a royal notary in the jurisdiction of Montreal. Since his commission does not seem to have been registered in Montreal and there is no trace of a Decoste notarial registry, it may be assumed that he never practised as a notary. Two years later, on 3 March 1753, he became a “process server,” and continued in this occupation until the conquest. But although his honesty and his assiduity in taking the sacrament had been extolled by witnesses at the investigation into his character, it seems that Jean-Christophe began to lead a dissolute life, despite the indignation and constant remonstrances of his parents. He paid no heed and married a widow of no means and little repute, Marie-Joseph Dumouchel. The marriage further displeased his parents, and by an act drawn up before notary Gervais Hodiesne* on 22 Nov. 1757 they disinherited their son, thus banishing him from the family. Jean-Christophe died on 18 Nov. 1767; a few days earlier he wrote that “he has no reason to be content with the way he has been treated by his brothers and sisters, who on different occasions have insulted him in public. ”
ANQ-M, Doc. jud., Pièces détachées, 7 mars, 25, 27 avril, 3, 4 mai, 6 juin, 19, 27, 30 juill., 17 sept., 30 déc. 1731, 2, 3, 5 janv. 1732, 10, 13, 15 mars 1753, 5 janv., 27 mars 1759; État civil, Catholiques, Notre-Dame de Montréal, 18 août 1725, 15 août 1726, 18 févr., 2 mars 1728, 15 mars, 29 juill. 1729, 21 nov. 1757, 19 nov. 1767; Saint-Joachim (Pointe-Claire), 28 févr. 1778; Greffe de L.-L. Aumasson de Courville, 5 nov. 1767; Greffe de Gervais Hodiesne, 22 nov. 1757; Greffe de F.-L. Lepallieur de Laferté, 23 nov. 1738; Greffe de M.-L. Lepallieur de Laferté, 16 août 1725; Greffe de Pierre Panet, 18, 19 nov. 1757; Greffe d’André Souste, 17 sept. 1754. C.-J. Ferrière, Dictionnaire de droit et de pratique, contenant l’explication des termes de droit, d’ordonnances, de coutumes et de pratique (3e éd., 2v., Paris, 1749). É.-Z. Massicotte, “Les tribunaux et les officiers de justice, à Montréal, sous le Régime français, 1648–1760,” RSC Trans., 3rd ser., X (1916), sect.i, 291, 293. P.-G. Roy, Inv. ord. int., II, 108, 126–27, 272; III, 43, 154–55, 205. Tanguay, Dictionnaire, III, 269. Vachon, “Inv. critique des notaires royaux,” RHAF, XI, 105.