The ENR was the national army of Italian dictator Benito Mussolini's Italian Social Republic (Repubblica Sociale Italiana, or RSI).

On 16 October 1943, the Rastenburg Protocol was signed with Nazi Germany and the RSI was allowed to raise four division-sized military formations.

Like the smaller RSI units—the Black Brigades and the Decima Flottiglia MAS—the newly formed RSI divisions generally participated in anti-partisan activities.

As the remaining divisions completed training, they were combined with German units and formed into Army Group Liguria.

The Army Group Liguria surrendered after being defeated at the Spring 1945 offensive in Italy.