AS

The as (plural asses), also assarius (rendered into Greek as ἀσσάριον, assarion) was a bronze, and later copper, coin used during the Roman Republic and Roman Empire.
The as was introduced in ca. 280 BC as a large cast bronze coin during the Roman Republic. In addition to the as, fractions of the as, the bes (2/3), semis (1/2), quincunx (5/12), triens (1/3), quadrans (1/4), sextans (1/6), uncia (1/12, also a common weight unit), and semuncia (1/24), as well as multiples of the as, the dupondius (2), sestertius (2.5), tressis (3), quadrussis (4), quinquessis (5), and denarius (10), were produced.
After the as had been issued as a cast coin for about seventy years, and its weight had been reduced in several stages, a sextantal as was introduced (meaning that it weighed one-sixth of a pound). At about the same time a silver coin, the denarius, was also introduced. Earlier Roman silver coins had been struck on the Greek weight standards that facilitated their use in southern Italy and…