Antoine Theodore Bernex was born in Marseilles on March 21, 1813. He was the second son of Anthelme Bernex (1777-1848) and Anne Marie Eudoxia Phillippon. His mother was the duaghter of a wealthy wallpaper manufacturer whose stores were located on Paradise Street, Marsailles. Hence, his father was sometimes called "Bernex-Phillippon".

Antoine Theorodre Bernex married Marie Louise Marguerite Lami Pivot (Born circa 1810). They had two surviving children including Anne Bernex Phillippon an Berthe Bernex Phillipon. Berthe would come to marry at age sixteen the 2nd Viscount de Torre de Moncorvo, Tomas Inacio de Moraes Sarmento. They were the parents of Maria Luisa de Moraes Sarmento. Her second husband was Admiral Arturo Costantino of the Kingdom of Italy.

Antoine was an enineer. Early in his career, he wrorked in the manufacture of wallpaper. Later, he had an interest in a massive development project along the Avenue du Prado that was designed by his father. Antoine launched an insurance company, "Le Midi". He became an Alderman in 1858 and further contributed to the transformation of Marseilles; piercing of Imperial Street, currently called The Republlic Street; construction of the barracks of St. Charles Street; development Noailles, etc.

In 1864, Antoine Theordore Bernex became the final mayor of Marseilles under the Empire of Napleon III. He continued to focus on a policy of urban development works counting the extension of thirty street including Paradise Street to the Prado; completion of the Palais Longchamp by the architect Esperandieu. His generous conduct during the cholera edpidemic of 1866-67 led to his being awardede the Legion of Honor and Officer of Ordert of St. Maurice and Lazarus. Apparently, he remained loyal to the old Empire after the fall of Napoleon III although he was retired. Antoine Theodore Bernex died in Marseilles on December 9, 1889.

In 1936, Maria Luisa de Moraes Sarmento Costantino, the widow of Rear Admiral Arturo Costantino, would remember her grandfather Antoine as a very good looking French gentleman, who simply idolized her.  She added that, “after he had made no end of mistakes in the stock market, he lost all at once, about every penny he possessed; and after a fit passed away and left my mother very little to live on.”