Louis-Marie-Florent de Lomont d'Haraucourt, marquis later duc du Châtelet , was an aristocratic French Army general and diplomat of the Ancien Régime.
Background
The son and heir of the noble and ancient Châtelet family, his mother, Émilie du Châtelet, famously was a scientist and the lover of Voltaire. On 20 June 1725, his father Florent-Claude du Chastelet married Gabrielle-Émilie, daughter of Louis Nicolas le Tonnelier de Breteuil.
Career
The Duke served as Governor of Semur-en-Auxois in Burgundy as well as Ambassador to the Court of St James's, besides other appointments, before being guillotined in 1793 aged 66. Like many marriages among the French nobility, theirs was an arranged marriage. The couple found they had little in common, but proprieties were observed in accordance with contemporary norms.
The Marquis and Marchioness produced three children: Françoise-Gabriel-Pauline (1726-1754), duchesse de Montenegro, Louis-Marie-Florent (later duc du Châtelet) and Victor-Esprit (born and died 1734). Marriage The Duke of Châtelet married, in 1752, Diane-Adélaïde de Rochechouart (died 1794) but they had no children.