His older brother Charles Emmanuel IV abdicated in 1802 and Victor Emmanuel succeeded him . Charles Emmanuel himself took little interest in the rule of Sardinia , living with his wife on the mainland in Naples and Rome until his wife 's death in 1802 , which led the childless Charles Emmanuel to abdicate the throne in favor of his younger brother . Aosta took the throne on June 4 , 1802 as Victor Emmanuel I. He ruled Sardinia from Cagliari for the next twelve years , during which time he constituted the Carabinieri a Gendarmerie corp , still existing as one of the main branches of military of Italy .