Caracalla

Co-emperor with his brother Geta after Septimius Severus's death; he had Geta murdered in their mother Julia Domna's arms within months. The Antonine Constitution of 212 extended Roman citizenship to every free man in the empire — a fiscal measure as much as an idealistic one, since it expanded the inheritance-tax base. Murdered by a disgruntled soldier in Mesopotamia while urinating by the roadside.