People have hoarded coins for their bullion value for as long as coins have been minted. However, the collection of coins for their artistic value was a later development. Evidence from the archaeological and historical record of Ancient Rome and medieval Mesopotamia indicates that coins were collected and catalogued by scholars and state treasuries. It also seems probable that individual citizens collected old, exotic or commemorative coins as an affordable, portable form of art. According to Suetonius in his "De vita Caesarum" ("The Lives of the Twelve Caesars"), written in the first century CE, the emperor Augustus sometimes presented old and exotic coins to friends and courtiers during festivals and other special occasions.