Coins have their roots deep in the lands of Ancient Rome. They still continue to be in circulation around the world, every country having its own mint and coin denominations. Some countries reintroduce some denominations in their economy, like the United States who had their dollar coin reintroduced.

When the Roman Republic was created barter system was widely used. The standard of exchange within the Republic's boarders was cattle – pecus. The latter was the word, from which pecunia derived. Pecunia was a Latin word for money. Later, in addition to the barter system, Romans started using pieces of bronze which were exchanged for various goods. The bronze pieces were called aes rude.

In order to be able to denote weight and worth of the bronze coins Romans started adding markings. This began in the first half of the third century. Thus the coin called as was equal to on Roman pound or libra, which weights about 335.9 grams. It became the main exchange unit within the Republic. The as was divided into 12 smaller units. These were called aes grave, which weighted a Roman uncia. The lesser denominations of Roman coins received the following names: semis (half-as), triens (third-as), quadrans (quarter-as), sextans (sixth-as), and uncia (twelfth-as).

Having trade with the Greeks the Romans thought of minting silver coins. The event happened in the year 269 BC. In minting their coins the Romans used the Greek style for another hundred years. Later, in 187 BC, the Romans rebuilt their monetary system and thus denarius[³²] appeared. Denarius was a silver coin, the value of which was 10 asses.

As decreased in value due to the Punic Wars. In 130 BC a denarius was worth 16 asses. Despite this fact both denominations remained in circulation throughout the existence of the Roman civilization.

The starting point of Imperial age rise under Augustus was marked by new Roman currency. The new coins were minted of four metals: gold, silver, brass, and bronze (or copper). The most widely used Roman currency of that time was aureus[³¹]. It was launched for the first time during the Second Punic War. At this time both denarius and as were still in circulation. Salaries were mostly paid using gold and silver coins. The daily transactions, however, often required brass and bronze coins.

Interesting to note that Roman currency was created in the Temple of Juno Moneta, located on the Capitoline Hill. The English word "money", by the way, comes from the Roman word "Moneta". The Senate was responsible for minting the coins. Tresiviri monetales were the junior magistrates that were those particularly responsible for issuing the Roman coins. The Roman Empire had different cities that minted gold and silver coins. Brass and copper Roman coins were made in mints located in several provinces.

Below there is the most widely used denominations. These include their relative value after 201 BC, the time of the Second Punic War. Each denomination's value is based on the as: