The archaeological find you see above is called an “aureus” and is one of the most valuable and high-quality coins that were issued, minting and distributed during the late Roman Republic and Empire, up until the about the 4th century.
According to finds.org.uk, the majority of Roman coins we have in museums, collections and private ownership were produced during the 4th century, the era which is generally regarded as Rome’s greatest moment of demise. Archaeological discoveries of Ancient coins are made extremely frequently, due to the scale that most currency was crafted on; usually Roman currency is dug up on previously Roman-occupied territories.
Most historians and archaeologists would agree that the first forms of currency in the Roman state appeared in the early Republic, but these were only crude devices of trading and would have to improve over time. Following the founding of Rome, purchases were made using valuable jewellery, cattle, sheep or other possessions. There was no organised system of money as such.
Gold and silver were the main components of Roman coins as these were valuable but also easy to mine from Rome’s vast provinces, notably during the 1st and 2nd centuries AD and the “Pax Romana”. To judge their authenticity, they would be weighed to gauge the amount of rare metal substance in them. On a while, this worked fairly effectively. However, in the bustling marketplaces, shops and slums of Rome and its other cities, this practice was not always carried out and the system depended heavily on trust.
One of the main reasons Roman leaders and the Senate catalysed the rising popularity of currency in Roman territory was because they were eager to utilise the important and lucrative trade routes between Etruria in the North and Hellenistic Colonies in the South. In 211 BC, the Denarius, the most common and recognisable coin in Roman currency, was introduced, along with a more uniform organisation for pecuniary matters. Rome continued to use silver in its coins but many were now bronze, with less value.
The Romans were pioneers and unifiers, inventing a currency which could be used all over the Empire. This meant that the value of coins and goods stayed similar from one region to the next, allowing someone to easily buy something in Gaul and then in Syria.
Throughout the Imperial Period, the worth of coins remained relatively stable despite some incidents of fake-coin making and lightening of currency pieces. On the other hand, the types, sizes and shapes of Roman coins changed constantly, as did the images printed onto them. During the Republic deities were most commonly etched into coins, as they were highly respected and loved by the Roman people. For example, Castor and Pollux remained a major icon of Roman currency for several centuries.
It was the victorious general and dictator, Julius Caesar, who was the first to formally print his own head-image onto a coin, starting a tradition that lasts into the modern-day. It was a form of propaganda, and it was believed that Caesar was attempting to portray himself as a god. This may be one of the reasons he was assassinated in 44 BC. However, his legacy lived on.
“Colchester and London were Britain’s major minting centres”
From that point, whenever a victorious general entered Rome and had ascended to dictator or emperor, his face would be printed on the currency for his rule.
The Senate often interfered when it came to money. Following the death of the tyranny Caligula, who made his horse a member of the Senate and commanded his men to stab the seawater as part of a war against Neptune, the Senate removed his image from all coins and cancelled much of the trading which involved coins bearing credit to him.
In the 3rd, 4th and 5th centuries, inflation gradually kicked in, making the denarius progressively less valuable. With many barbarians smithing take coins and attempted to bypass Roman currency laws, the system began to fall apart. Coins fell out of use within the fracturing Germanic kingdoms and did not appear again into around the Middle Medieval Age.