Wounded twice, he was promoted by delegation to Chef de bataillon (Commandant – Major), based on the recommendation of général Henri Joseph Eugène Gouraud.

Under his command, the regiment covered itself with excellence during combats of Hangard-en-Santerre, La Montagnde de Paris, then in piercing the Hindenburg Line, a combat battle which would later be designated as the anniversary of the 3rd Foreign Infantry Regiment 3e REI, heir to the traditions of the R.M.L.E.

He would remain until planning the 100th anniversary (the centennial) of the French Foreign Legion on Cameron day of 30 April 1931.

[7] On 1 April 1931 Rollet assumed command tenure as the 1st Inspector of the Foreign Legion, a post which he specifically created under his intentions.

In his final years of service, he dedicated his career to the organization of the modern French Foreign Legion and the realization of considerable social profits to active legionnaires as well as those on retirement.

Rollet made major contributions to promoting and preserving the Legion's history, traditions and mystique.