Pierre-Marie-Louis de Boisgelin de Kerdu

Pierre-Marie-Louis Kerdu was born on 5 May 1758 at the Château of Ville-Balin in Plélo, Brittany to Claude Jean Marie, Comte de Boisgelin and Jeanne Ammanuelle du Hallay de la Borderie. Pierre studied at the Saint-Sulpice seminary and later presented to the Order of Saint John of Jerusalem on 8 August 1782.[1][2] In 1784 he was commissioned into the French Royal Army as a Sous-lieutenant in the Régiment du Roi (King's Regiment), where he developed a close friendship with the Comte de Plies, Duc de Fortia. The two became so close they began using the pseudonym of 'Caillot-Duval' for their letters.

In 1788, Pierre was promoted to Lieutenant, but left France that year to travel Central Europe and Russia. In 1793, following the French Revolution, Pierre abandoned the Knights, but remained in Malta.

In London, Pierre published his best known book, Ancient and Modern Malta, containing a description of the ports of the islands of Malta and Gozo in 1804. In 1809, he published a further three-volume article on the Knights, entitled "Ancient and Modern Malta, containing the description of the island... the history of the Knights of Saint John of Jerusalem until the year 1800 and the account of the events which accompanied the entry of the French into Malta and its conquest by the English".[3]

In 1815, following the Bourbon Restoration, Pierre returned to France but was never able to obtain a pension from the new king for himself or any soldiers of the Régiment Royal Louis. On 9 September 1816, Pierre died at the age of 58.

In 1793, he traveled to Toulon, which had just given itself up to the British as a result of the Federalist revolts. Soon after, through a secret agreement with Louis Stanislas Xavier, Comte de Provence, he organised the Régiment Royal Louis, the only regiment in the name of King Louis XVII. Soon after, he became Captain of the Grenadier Company (Compagnie des Grenadiers). After the death of Major Hustin during the Siege of Toulon, he became commanding officer of said regiment until its disbandment in December 1794; and subsequently he retired. Because the regiment had been under his command for the majority of its duration, it is sometimes referred to as the Régiment de Boisgelin.[4][5]

• Atkinson, C. T. (1943). Foreign Regiments in the British Army, 1793–1802 Part V – The Mediterranean and Southern Europe. Journal of the Society for Army Historical Research, Winter 1943, Volume XXII, No. 88 (Winter, 1943). Society for Army Historical Research.
• Atkinson, C. T. (1944). Foreign Regiments in the British Army, 1793–1802 Part VI – Notes on Each Corps or Regiment, Section IV – Royal Louis to York Rangers. Journal of the Society for Army Historical Research, Autumn 1944, Volume XXII, No. 91 (Autumn, 1944). Society for Army Historical Research.
• Abbé Joseph de Boisgelin, ''La Maison de Boisgelin'', 1985.
• Paul Lacroix  (dit le Bibliophile Jacob), ''Histoire des mystificateurs et des mystifiés'', Paris, 1875.
• Iorédan Larchey, ''Les mystifications de Caillot-Duval : avec un choix de ses lettres les plus étonnantes : suivies des réponses de ses victimes'', Paris, 1864.
• Iorédan Larchey, ''Les Mystifications de Caillot-Duval, choix de ses lettres les plus amusantes avec les réponses de ses victimes''. Nouvelle édition... P., Daragon, 1901.
• Jean Vartier, ''Alphonse de Fortia'', France-Empire, 1985.