quadrigatus

thumb|350px|Didrachm or quadrigatus (ca. 225–212 BC), with a laureate head of [[Janus or the twinned Dioscuri, and Victory driving a quadriga (four-horse chariot)]] The quadrigatus was a medium-sized silver coin produced by the Roman Republic during the 3rd century BC. The obverse featured a young janiform bust and the reverse featured Victory driving a quadriga (four-horse chariot), giving the coin its Roman name, with the inscription "ROMA" below.

The coin weighed about 6.8 grams (6 scruples), consistent with the weight of a south Italian Greek didrachm. It was minted for a number of years until shortly before the introduction of the denarius (a few years before 211 BC). Gold coins with similar obverse types were also issued at about the time that the quadrigatus was discontinued (staters and half-staters) which featured the same obverse type as the quadrigatus and the reverse type of two soldiers performing an oath over a third soldier holding a pig, with the inscription "ROMA" below. The choice of Janus for these coins is believed to coincide with the closing of the doors of the Temple of Janus, indicating the absence of warfare, a rare occasion. Michael Crawford, however, has suggested that the janiform head is more likely to have represented the Dioscuri, since Janus is usually a mature and bearded figure.