He specialized in meticulously researched paintings of ancient Rome, especially depictions of women. He was best known for a series of some thirty paintings which spanned his entire career, depicting Vestal virgins. His daughter, Laura Leroux-Revault , was also a painter.
From to , first the General Council of the Meuse and then the city of Verdun granted him annual scholarships to pursue his education in Paris. It was in Picot's studio that he met his lifelong friend Jean-Jacques Henner. He supported himself by working as a lithographer and as an illustrator for fashion journals.
In , , and he entered the annual competition for the Prix de Rome , administered by the Institut de France , which awarded the Grand Prix winner a multi-year scholarship to study and paint in Rome. He came close; his painting for , when the assigned subject was the resurrection of Lazarus, received the Premier Second Grand Prix.
The commission paid for his travel and provided lodging at the French Academy in Rome , alongside the winners of the Prix de Rome. Leroux arrived in Rome on March 12, After his copy of Titian was completed and sent to Paris, Leroux stayed on in Rome, supporting himself, alongside Henner, by painting picturesque scenes for the foreign tourists. He and Henner also traveled beyond Rome, including trips to Pompeii, immersing themselves in the landscapes, art, and archeology of Italy. Leroux lived seventeen years in Rome, with excursions across Italy and beyond to Greece, Asia Minor, Turkey, and Egypt, as well as some return trips to France.
Both were set in the ancient world, and both depicted women in religious contexts. Croyantes shows two women helping an ailing supplicant to approach a statue of a goddess in hopes of obtaining a divine cure, while Une Nouvelle Vestale depicts a candidate for the chaste life of a keeper of the holy flame of Vesta , protector of the city of Rome.
