After Henri-Philippe Petain signed the armistice with Germany in June, 1940, a group of students at the Sorbonne established the resistance group, Défense de la France. The group produced a clandestine newspaper, Défense de la France. Over 15,000 copies of the first issue appeared in August 1941.
Helene Viannay was in charge of Rotaprint that she kept hidden in the physical geography laboratory in the Sorbonne. She also took charge of distribution. A total of 47 clandestine issues of the paper appeared over the next three years. Circulation gradually increased and over 450,000 were printed in January, 1944.
The Défense de la France also established intelligence and escape networks. It also used its printing facilities to produce false papers for the French Resistance. In the later stages of the Second World War the organization worked very closely with the Maquis.