Louis Alexandre de La Rochefoucauld d'Enville

Louis-Alexandre de La Rochefoucauld (4 July 1743, Paris - 4 September 1792, Gisors, Normandy) was a French nobleman and politician. He was a member of the House of La Rochefoucauld (one of the oldest and most famous French noble families, originating in La Roche in the 10th-11th centuries) and a major lord under the Ancien Régime. He also played a political role in 1789 early on in the French Revolution before being executed in the September Massacres. He was a duke, initially with the title 'duc d'Enville' or 'duc d'Anville' and later with that of 6th duc de La Rochefoucauld. He was a cousin to François Alexandre Frédéric de La Rochefoucauld-Liancourt and Ambroise-Polycarpe de La Rochefoucauld-Doudeauville.

He was a son of Jean-Baptiste de La Rochefoucauld de Roye (killed in the 1746 Duc d'Anville expedition) and Marie-Louise-Nicole de La Rochefoucauld. In 1762,he married Louise-Pauline de Gand de Mérode, but they had no children. That same year he inherited the title of duc de La Rochefoucauld on the death of his grandfather Alexandre de La Rochefoucauld (29 September 1690 - 1762). His second marriage was in 1780 to his niece Alexandrine Charlotte de Rohan-Chabot - this marriage was also without issue.

He was one of the keenest French defenders of the American Revolution, befriending and translating for Benjamin Franklin - in Paris in 1783 he and Franklin published Constitutions des Treize États-Unis de l'Amérique (Constitutions of 13 United States of America). He was also passionate about natural sciences and travelled to England, Sweden (where he became a member of the Royal Swedish Academy of Sciences), Germany, Switzerland, Italy and Savoy. His friends also included Desmarest, Dolomieu, Saussure, Turgot, Condorcet. He served as president of the Société royale de médecine and the Académie royale des sciences.

...
Wikipedia