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 Augustus (27 BC-AD 14) based the coinage on the aureus
        of 1/42 of a pound of gold, equivalent to 25 denarii,
        each of 1/84 of a pound of silver, the metals being
        struck almost pure. The denarius was valued at 16 asses.
        Token coinage consisted henceforth of brass sesterces and
        dupondii (equal to four and two asses, respectively),
        with copper asses, halves, and quarters, the as being the
        most common. Nero in AD 64 lightened aureus and denarius
        to 1/45 and 1/96, respectively, but debasement of silver
        subsequently took place. Under Septimius Severus it
        reached 40 percent, and Caracalla issued a debased double
        denarius of the weight of only 1 1/2 denarii. Gallienus'
        double denarius of copper and silver, leached to give a
        more silver-rich surface, marked a monetary breakdown,
        only partially cured when Diocletian and Constantine
        again made gold the firm basis for supplementary pure
        silver and abundant copper coinage. Augustus' earliest gold and silver were coined chiefly
        in the east - e.g., at Ephesus and Pergamum - and more
        briefly at Emerita in Spain. Bronze also was mainly
        eastern, though some was struck at Nemausus (Nîmes). The
        Rome mint was reopened c. 20 BC for gold and silver and
        remained open for this purpose until c. 12 BC; its bronze
        continued irregularly. From 12 BC, Lugdunum (Lyon), with
        other mints of uncertain identity, undertook the main
        western coinages in gold, silver, and bronze. After 64
        Rome was once more the chief mint for all metals.
        Official mintages were supplemented by a mass of regional
        or local coinages, while official coinages from eastern
        mints provided necessary currency for local Roman
        frontier forces. The bronze of Rome was marked S(enatus) C(onsulto) and
        continued to bear the names of the tresviri
        monetales - masters of the mint, now reduced to their
        traditional number - until
        4 BC. But S C also appeared on bronze from Lyon and
        Antioch in imperial provinces, showing that whatever
        nominal senatorial rights of coinage still lingered
        on - the
        tresviri are known until the 3rd century - the emperor
        wielded effective control over all metals everywhere.
        This was logical, since his economic powers were equally
        comprehensive. In fact, the old senatorial mint was
        transferred from the temple of Juno Moneta on Rome's
        Capitoline Hill and merged, probably after the fire of 64,
        with an imperial mint for gold and silver elsewhere in
        the capital. Henceforth, it worked in sections - six were
        normal later - controlled immediately by an imperial
        procurator and staffed by slaves or freedmen. |  |