In 1844, his brother Kalmus "Calmann" Lévy (1819–1891) joined the publishing house.

It was the publisher of most of the important French authors of the second half of the 19th century, including Balzac, Baudelaire, René Bazin, Gabriele D'Annunzio, Dumas, Flaubert, Victor Hugo,[3] Lamartine, Ernest Renan, George Sand, Stendhal.

[5] In 1893, Calmann was succeeded by his sons Georges, Paul, and Gaston, who went on to publish authors including Anatole France, Pierre Loti and Proust.

[6][7] During Nazi occupation, Gaston Lévy was interned, and the publishing company, run by the Germans, was renamed Éditions Balzac in 1943.

Authors edited in the postwar period include: Arthur Koestler, Elia Kazan, Anne Frank, and later Donna Leon, Nicolas Hulot, Patricia Cornwell, Guillaume Musso, among others.