The finances of the Roman Republic, including its coinage, were governed by the Senate. A board of three moneyers, the tresviri monetales, was in charge of the mint.
From about 208 BC, the tresviri monetales began to mark all coins with small symbols, letters, or monograms. These signs designated the magistrate responsible for the production of a certain coin series, and where it had been struck. Any discrepancy in weight and fineness of a coin could thus be sanctioned.
The coin symbols are evidence for the rigid state-controlled organization of Roman coinage. The symbol on the reverse of this denarius is a Gallic shield and a carnyx. What it stands for – whether for a moneyer or a mint – is unknown, however.