On 2 October 1943, Heinrich Himmler and Gottlob Berger devised the Programm zur Aufstellung der italienischen Milizeinheiten durch die Waffen-SS ("Program for the deployment of Italian militia forces by the Waffen-SS") which was approved by Adolf Hitler and Benito Mussolini.

The unit was commanded by SS-Obergruppenführer Karl Wolff and called Italienische SS-Freiwilligen-Legion, but soon renamed 1.

In April 1944, three battalions fought against Allied bridgeheads of Anzio and Nettuno with good results, for which Heinrich Himmler on 3 May 1944 allowed them to wear SS-Runes on black rather than red and be fully integrated into the Waffen SS.

[1] Members of the "Vendetta" under former Blackshirt Lieutenant-Colonel Degli Oddi particularly distinguished themselves in defeating a determined effort by the U.S. 3rd Infantry Division to overrun their positions and capturing a number of prisoners.

In the spring of 1945, the division under the command of Ernst Tzschoppe as Kampfgruppe Binz fought against French units in Lombardy and the Partisans in Piedmont.