As to why Aureolus is credited with suppressing the Macriani as a major challenge to Gallienus's rule rather than the Emperor himself there are two possible explanations: (1) The determination of the Latin historians to denigrate the achievements of Gallienus; however, a more likely explanation is that (2) Gallienus was attempting at this time to crush the Gallic usurper Postumus who he probably saw as an even greater threat to his regime than the Macriani and to clear the Juthungi out of the Alpine province of Raetia where they posed a direct threat to Italy and Rome.