This is a Roman gold coin from the reign of the Emperor Nero, dated to 65 AD.
It’s about the size of a modern 20p coin, but thicker. The front shows Nero’s head, and the back (seen here) shows a closed door – which is pretty strange, if you don’t understand the meaning. In a time with no newspapers, TV, radio or internet, coins were the mass media of their day – a way for the Emperor to spread official news to the entire empire, and the inscription around the edge of the coin explains the image, but even those who couldn’t read would have understood it.
There was a custom in ancient Rome to open the doors to the temple of Janus (the God of beginnings and endings, for whom January is named) whenever the Empire was at war. Given the size of the empire, and its often military attitude, Nero was proud of the fact that the whole Empire was briefly at peace, and he was able to have the doors of the temple closed, so he publicised it with this coin design. The inscription reads – IANVM CLVSIT PACE PR TERRA MARIQ PARTA – which roughly translates as “The peace of the Roman people, over land and sea, the doors of (the temple of) Janus are closed.”