Jean-Louis-Paul-François de Noailles, 5th Duke of Noailles (26 October 1739, Paris20 October 1824) was a French nobleman and scientist. Early life Jean-Louis-Paul-François de Noailles was the son of Cathérine Françoise Charlotte de Cossé-Brissac and Louis, 4th duc de Noailles, a Marshal of France in 1775. His father was a nephew of Marie Victoire de Noailles, daughter-in-law of Louis XIV of France, and his paternal grandmother, Françoise Charlotte d'Aubigné, was a niece of Madame de Maintenon. He was in the army for a period. However, his eminence as a chemist gained him the election as a member of the Académie des sciences in 1777. He was also a Knight of Golden Fleece. He became Duc d'Ayen in 1766 on his grandfather's death, and Duc de Noailles on his father's in 1793. Having emigrated in 1792, he lived in Switzerland until the Bourbon Restoration in 1814, when he took his seat as a Peer of France. French Revolution As a member of the royal military the Duke was away from his estates during much of the French revolution and was not present for the death of his father, upon which he became the Duc de Noailles. His absence spared him being arrested along with most of his relatives on orders of Robespierre in May 1794. On 22 July that year, his 70-year-old mother (the dowager Duchess Françoise de Noailles), his wife (the Duchess Anne-Louise-Henriette), their eldest daughter Louise (the Vicomte de Noaille, by virtue of marriage to her cousin Marc Antoine de Noaille), and their second daughter, Adrienne de La Fayette, were condemned to the guillotine. All were executed except for Adrienne, who was spared at the last moment due to intervention by the future American president, James Monroe (the then U.S. Minister to France), because of her husband's efforts for America during the American War for Independence) but only after her paternal grandmother, mother, and sister were beheaded within her sight. The Duke learned of their deaths weeks later. His family had lost many other members including two of his uncles (including Philippe de Noailles, duc de Mouchy) and numerous cousins and in-laws during the Revolution. The Duke went into self-imposed exile in Switzerland until the Bourbon Restoration, returning to France and his ravaged estates after Napoleon and the Directory restored some order. Through the efforts of his daughter Adrienne de La Fayette, whose husband's family also suffered greatly in the