During the Siege of Paris by the Germans (September 1870–March 1871), he took part in the Blanquist uprising of October 31, 1870, against the government of National Defense.

On January 26, 1871, upon the announcement of the armistice with the Germans, he attempted to seize the forts in eastern Paris; he was arrested and sentenced to prison.

On March 18, 1871, at the start of the Parisian uprising against the government of Adolphe Thiers, he captured the Prince-Eugène barracks.

On March 24, 1871, he led the attack against the town hall of the 1st arrondissement of Paris, in the company of Maxime Lisbonne and Eugène Protot.

The same day, he was named general of the commune (with Émile Eudes and Émile-Victor Duval).