Guillaume de Castelnau
- Born on April 20, 1726 in Pontacq
Parents
- Philippe de Castelnau (1698 - ), marquis de La Loubère
- Marie de Montesquiou (c. 1710 - )
Family
- Married on February 21, 1759, with Catherine du Barry (c. 1739 - 1767), fille, issuing
- François Anselme (1760 - )
- Jean Cécile (1762 - )
- Jean Louis Alexandre (1763 - 1794)
- Jean Paul Isidore (1764 - )
- Married on June 30, 1795 in Tarbes, with Marie Jeanne Sirieix (c. 1750 - ), issuing
- Jacques (1774 - )