Haro, a painter and a student of Ingres and Delacroix (whose portraits he painted in 1866 and 1868), was also their regular supplier of canvases, stretcher bars, frames, paints, and so on.
The sign on the family-run shop, located near the Rue de Petits-Augustins, read: "Au génie des arts" ("In the Spirit of the Arts"). Étienne’s parents ran the store before he took over and transformed it into a large company that repaired, restored and remounted paintings. Haro was a painting restorer for the Palais des Tuileries and the Ministry of Public Works (his father and uncle, M. Rey, had both worked for the Ecole des Beaux-Arts and for the Institut).
He worked alongside Delacroix preparing the Galerie d’Apollon in the Louvre. In 1857, he told the painter about the apartment at 6 Rue de Furstenberg and insisted that he sign a lease, saying that it was an "admirable" deal in every way. He felt it was fully worthy of the artist, as it was situated near the Institut, to which Delacroix had been admitted, and faced a garden reserved solely for the tenant of the apartment.
Indeed, Delacroix trusted Haro, to whom he gave the task of bringing together the paintings that were to be exhibited at the Universal Exhibition of 1855.