A partisan of the « Commune »
Rossel was born into a republican, protestant family from the Cévennes region. His father, an Army officer, refused to swear allegiance to Napoleon III.
He was admitted to the Ecole Polytechnique in 1862. He was a bright student and on left Polytechnique as an Army. In 1870 he took part in the siege of Metz with the rank of captain under the orders of a fellow Protestant, General Sigismond de Berckheim ; he made known his disapproval of the strategy of Bazaine. His refusal of defeat and his republican opinions led him to join the “Communards” in 1871. Promoted to General by the latter, he was nevertheless faced with a certain lack of understanding which will even lead to his being disowned by his former friends at the end of the “Commune” period. Nevertheless, he is arrested by the Versaillais and sentenced to death.
In his prison cell, he wrote his memoirs, analysing the difficulties he had encountered, and concluded by underlining the need for education of the working class.