Berthier accompanied Napoleon throughout the campaign of 1796, and was left in charge of the army after the Treaty of Campo Formio. He was in this post in 1798 when he entered Italy, invaded the Vatican, organized the Roman Republic, and took Pope Pius VI prisoner. Berthier supervised the Pope’s relocation to Valence, where, after a tortuous journey, Pius died. The death of the Pope dealt a major blow to the Vatican's political power which, however, did not prove as ephemeral as that of the First French Empire.