Treves published the first Italian translations of works by foreign writers such as Flaubert, Zola, Bourget, Maupassant, Tolstoy, Dostoevsky, Turgenev and Gorky, Sienkiewicz and Samuel Smiles.

Between the end of the century and the beginning of the next, two new illustrated newspapers came out: Corriere illustrato (weekly, which however suffered competition from Luigi Albertini's powerful Domenica del Corriere) and Il Secolo XX (1902 [9] - 1913 [10 ]; in 1927 it passed to Rizzoli, which published it until 1933, a monthly, conceived in response to La Lettura, another creation by Albertini), in which Gabriele D'Annunzio, Raffaello Barbiera, Ada Negri and Ugo Ojetti collaborated.

[3] In 1904, after the premature death of Giuseppe Treves, Emilio decided to open the publishing house to external sources of financing, setting up an anonymous company.

The activity of the publishing house went through a period of constant expansion: in the decade 1900-1910 production rose from 88 new titles a year to 188 (not counting the reissues of dictionaries and school books).

by Sienkiewicz in 1914 which, in an unusual editorial initiative for the time,[5] was accompanied by 78 still photographs taken from the homonymous film by Enrico Guazzoni, released in 1913.

He also kept a first-rate catalogue: he published works by Giuseppe Antonio Borgese, Marino Moretti, Ugo Ojetti, Alfredo Panzini, Grazia Deledda, Luciano Zuccoli, Rosso di San Secondo and Sem Benelli.

In 1939, the Forlì-based industrialist Aldo Garzanti took over the company, immediately changing its name to comply with the fascist racial laws (the Treves were a Jewish family).