Augustus promoted a wide-ranging programme of State reorganisation, which also affected the coinage system. This emperor minted in gold, silver, orichalcum and copper, establishing the weights and the relation of values between the different coins. During Augustus' reign a custom was imposed that had begun with Julius Caesar, and which later became more and more frequent. This was engraving the portrait of the ruler of Rome on the obverse of the coins. On this aureus of 'Lugdunum', present-day Lyon, we see the portrait of Augustus, surrounded by the inscription AVGVSTVS DIVI F(ilius), that is, proclaiming himself to be the son of the divine Julius Caesar. Engraved on the reverse was a bull in the act of charging and the inscription IMP XII, which indicates that Augustus had received the 'imperium', or command of the Roman armies, for the twelfth time.