Costa de Beauregard was born at Bouvesse-Quirieu on 19 June 1806. He was the eldest son, and third child, of Henri Maurice Victor François Régis Costa, Marquis de Beauregard and Catherine Élisabeth de Quinson. He was a grandson of Joseph Henry Costa de Beauregard, who was raised Marquis de Beauregard by the Duke of Savoy in 1700 by letters patent.
Beauregard refused a seat in the Senate proposed by Emperor Napoleon III in 1860, however, he became general councilor of the canton of Chambéry-Nord the same year and was elected president of the new General Council of Savoie, holding these offices until his death in 1864. In his role as president of the Council, and together with Baron :fr:Frédéric d'Alexandry d'Orengiani|Frédéric d'Alexandry d'Orengiani (the mayor of Chambéry and the first Senator of Savoie, he welcomed Napoleon III and Empress Eugénie on 27 August 1860 during the imperial trip to Savoy. During their visit, a ball was given in their honor at the city theater, and the marquis danced with the Empress.
Personal life
On 12 May 1834, he was married to Marthe Augustine de Saint-Georges de Vérac, the youngest daughter of Euphémie de Noailles and Olivier de Saint-Georges de Vérac, Marquis de Vérac, a maréchal de camp who served as governor of the Château de Versailles. Together, they were the parents of eleven children, including:
Charles-Albert-Marie Costa, Marquis de Beauregard, who married Emilie Pourroy de l'Aubérivière de Quinsonas, a daughter of the Adolphe de Pourroy de l'Aubérivière, 4th Marquis de Quinsonas.
Camille-Josselin-Marie-Victor Costa, Marquis de Beauregard, who married Béatrix Marie Antoinette Budes de Guébriant in 1864.
Count Armand-Marie-Henri-Olivier Costa de Beauregard, the former secretary of the embassy.
Count Gabriel-Marie-Paul Costa de Beauregard, who married his cousin Marie-Pauline Herminie de Rougé, a daughter of Count Adolphe de Rougé and Marie de Saint-Georges de Vérac, in 1869.
Count Camille-Jean-Adolphe-Marie Costa de Beauregard, Canon of Chambéry.
Élisabeth Gasparine Marie Costa de Beauregard, who died young.
François-Marie-Pantaléon Costa de Beauregard, who died young.
Félicie-Louise-Marie Costa de Beauregard, who maried Henri Fernand Jules de Prunelé, Marquis de Prunelé of the Château de Trécesson in 1866.
Through his eldest son Charles, he was a grandfather of Léontine Marie Eugénie Costa de Beauregard, who married Armand Edouard Marie Georges, Prince de Broglie-Revel. Through his second son Josselin, he was grandfather of Ferdinand-François-Marie-Pantaléon-Victurnien Costa, Marquis de Beauregard, who married Marie-Madeleine-Emilie-Victorine-Augustine Crombez in 1886.
