The as (pl.: assēs), occasionally assarius (pl.: assarii, rendered into Greek as ἀσσάριον, assárion), was a bronze, and later copper, coin used during the Roman Republic and Roman Empire.
== Republican era coinage ==
The Romans replaced the usage of Greek coins, first by bronze ingots, then by disks known as the aes rude. The system thus named as was introduced in ca. 280 BC as a large cast bronze coin during the Roman Republic. The following fractions of the as were also produced: 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...