Jullien would likely have become a major player in the Revolution had it not been for the execution, by guillotine, of Robespierre in July 1794. Made destitute, he was arrested on August 10 and sent to prison; he would be held at the "maison de santé" of Notre-Dame-des-Champs, and would testify at Carrier's trial. He disavowed his association with Robespierre and was released, through the intervention of his father, on October 14, 1795. Ten days later, the insurrection of 13 Vendémiaire was stopped.