{"record":{"aliases":["Ludwig-Wilhelm Otto","Comte de Mosloy"],"appointmentIds":["france-1a40182c0bb234","france-c64c52d8f14009"],"appointmentsDataset":"https://chanceries.org/diplomats.json","archivalSources":[],"canonicalUrl":"https://chanceries.org/diplopedia/people/louis-guillaume-otto-fa9d2247d8/","countrySlug":"france","entityId":"https://chanceries.org/diplopedia/people/louis-guillaume-otto-fa9d2247d8/#person","eventIds":[],"expandedParagraphs":["Louis-Guillaume Otto entered French diplomacy through the service of La Luzerne, following him from Bavaria to the United States in 1779. Educated at Strasbourg, he worked as a private secretary and then succeeded Barbé-Marbois as legation secretary in 1785. His repeated periods as chargé d’affaires gave him experience of American government both under the Confederation and after the adoption of the federal Constitution.","One substantive assignment was France’s protest against American tonnage duties. In December 1790 and January 1791, Otto argued to Jefferson that the new federal charges on foreign vessels violated the commercial treaty of 1778 and sought repayment for affected French merchants. He also appealed to practical reciprocity, observing that more American vessels entered French ports than French ships entered American ports. Jefferson disputed the treaty interpretation, and Washington submitted the exchange and his secretary’s analysis to the Senate.","Returning to France, Otto worked in foreign affairs, was imprisoned during the Revolution, and later joined Sieyès’s embassy at Berlin. Sent to Britain initially to arrange prisoner exchanges, he became a peace negotiator. On 1 October 1801 he and Lord Hawkesbury signed the London preliminaries. The text provided for an end to hostilities and a broad settlement of colonial and Mediterranean possessions, while reserving details for the definitive peace that followed at Amiens.","Otto subsequently represented France in Bavaria and Austria and became count of Mosloy. He returned briefly to foreign affairs administration during the Hundred Days. After Waterloo, a projected mission to Britain concerning Napoleon did not proceed because he could not obtain passports. He retired from public life and died in Paris in 1817."],"id":"france:louis-guillaume otto","identifiers":{},"legacyPersonIds":[],"legacyUrl":"https://chanceries.org/diplomat-fa9d2247d8294ee2aa03.html","name":"Louis-Guillaume Otto","notes":[{"sourceIds":["mission-8b838c9175b12fd7a2d5","mission-a79af9b5a3368919ffeb","mission-4f192e1ef70db17feecb","mission-60f095a8410a52bce972"],"text":"The legation followed Congress to New York in 1786."}],"paragraphSources":[["src-18f231a1d85969e9"],["src-b166ca8edb983dde"],["src-18f231a1d85969e9","src-acc7cec275fb5b64"],["src-18f231a1d85969e9"]],"profileUrl":"diplomat-fa9d2247d8294ee2aa03.html","relatedEvents":[],"relatedPeople":[],"relationships":[],"researchStatus":"reviewed","reviewedOn":"2026-10-28","revision":"7209715b9fddc932","sources":[{"accessedOn":"2026-10-28","date":"2025-10-13","id":"src-18f231a1d85969e9","locator":"Full biography; disputed particulars excluded","publisher":"Didier Grau and Lionel A. Bouchon, Napoléon & Empire","title":"Louis-Guillaume Otto, Count of Mosloy","type":"reference","url":"https://www.napoleon-empire.org/en/personalities/otto.php"},{"accessedOn":"2026-10-28","date":"1791-01-19","id":"src-b166ca8edb983dde","locator":"Otto letters of 13 December 1790 and 8 January 1791; Jefferson report","publisher":"Yale Law School, Avalon Project","title":"George Washington, message to the Senate of 19 January 1791, with Jefferson report and Otto notes","type":"primary-record","url":"https://avalon.law.yale.edu/18th_century/gw013.asp"},{"accessedOn":"2026-10-28","date":"1801-10-01","id":"src-acc7cec275fb5b64","locator":"Preamble and articles 1–14","publisher":"Napoléon & Empire, historical document transcription","title":"Préliminaires de paix de Londres du 1er octobre 1801","type":"primary-record","url":"https://www.napoleon-empire.org/texte-officiel/paix-londres.php"},{"accessedOn":"","date":"","id":"mission-8b838c9175b12fd7a2d5","locator":"","publisher":"","title":"Louis-Guillaume Otto — mission record (1789–1791)","type":"Mission record","url":"https://afsa.org/sites/default/files/fsj-1955-10-october_0.pdf"},{"accessedOn":"","date":"","id":"mission-a79af9b5a3368919ffeb","locator":"","publisher":"","title":"Louis-Guillaume Otto — mission record (1789–1791)","type":"Mission record","url":"https://archivesdiplomatiques.diplomatie.gouv.fr/media/ddd06cdd-10ce-445c-8f53-cd91896b1b27.pdf"},{"accessedOn":"","date":"","id":"mission-6963b8acac13ceffd32d","locator":"","publisher":"","title":"Louis-Guillaume Otto — mission record (1789–1791)","type":"Mission record","url":"https://rotunda.upress.virginia.edu/founders/default.xqy?keys=FFCP-print-01-21-02-0004-0282"},{"accessedOn":"","date":"Accessed 26 October 2026","id":"mission-4f192e1ef70db17feecb","locator":"","publisher":"","title":"Historical representation: Kingdom of France","type":"Mission record","url":"https://www.elysee.fr/en/french-presidency/the-french-flag"},{"accessedOn":"","date":"","id":"mission-60f095a8410a52bce972","locator":"","publisher":"","title":"Louis-Guillaume Otto — mission record (1785–1788)","type":"Mission record","url":"https://csac.history.wisc.edu/european-assessments/"}],"topics":["tonnage duties","Treaty of 1778","Confederation","Peace of Amiens","prisoner exchanges"]},"schemaVersion":1}