Between 280 and 281, there was a civil war in Roman Europe. Bonosus and Proculus made themselves emperors. The "Historia Augusta" says that this was at Colonia Agrippina (Cologne), but this may not be correct. Not long after this, Probus's armies overcame the armies of Proculus and Bonosus at Colonia Agrippina. Bonosus may have killed himself and Probus may have executed Proculus.