The son of François Hyacinthe Arcambal (an employee of the French ministry of war) and of Thérèse Rosalie Pélagie Deshayes, Piscatory was born on 6 April 1800.

His diplomatic career began in 1841 - from June to September, Guizot, then French foreign minister, sent him to travel throughout Greece.

In September 1843, a coup broke out in Greece, forcing Otto to promise to convene a national assembly to create a Greek constitution.

Piscatory continued to satisfy his government and was made a peer of France on 21 July 1846 and a commander of the Légion d'honneur on 31 August 1846—a year in which French influence in Greece gave rise to the new and powerful instrument thanks to Piscatory's efforts and those of the French education minister comte de Salvandy.

Piscatory attempted to follow a political career under the Second French Republic and was elected representative for the département of Indre-et-Loire in the Assemblée législative on 13 May 1849.