[1] When in the 1930s, in the course of the Fascist government's program of railways development, a new locomotive was needed to provide a fast service on the newly electrified Milan-Rome mainline at 3,000 V DC.

This was also permitted by the introduction of new metallic passenger cars, capable of relative higher speeds.

A second order in the same series requested a shorter gear ratio (29/103) and larger air intakes, which caused an increase in weight of four tons.

The second series (81 units) differed in the removal of the frontal bonnets, replaced by a more profiled driving cabin: this set a style which was adopted for all the following Italian locomotives.

A third order was issued on April 5, 1939, for 80 locomotives, but the construction was halted by the outbreak of World War II after the completion of 39 units.