|The solidus was introduced circa 310 in the Western part of the empire by Constantine I ‘the Great’ (307-337). The new gold standard of the empire, the solidus was struck at 72 per pound (about 4.5 grams) on a comparatively broad and thin planchet. |
Solidus of Constantine I was struck at Antioch in about 324. It features a portrait of Constantine I on the obverse and the figure of the emperor on horseback on the reverse.
The solidus remained the standard gold coin for the rest of the Roman Empire and filled the same role for most of Byzantine history.