Coinage came into use in Asia Minor around 600 BC. By 500 BC its use had spread through the Greek world. Compared with other civilizations of the Mediterranean world, coinage came late into use in the Roman Republic. The Romans remained a primitive and eminently rural people until the late fourth century BC. They used livestock (pecus) and crude bronze bars (aes rude) as media of exchange. Latin preserved the memory of this period in its word to designate money, pecunia (from pecus). A similar system was used by other peoples in Italy, because there were no deposits of silver and gold there. Only the Greek colonies of southern Italy issued coins of these precious metals following the common practice in their mother cities. They obtained, however, these metals through trade.
The Law of the Twelve Tables (Lex Duodecim tabularum) demonstrates the use in Rome of the bronze pound (as, plural asses) as a way of measuring the value of properties in the V century BC. The memory of this primitive system was preserved for a long time. All transactions with these rough bronze pieces involved the use of a scale. Many centuries after the introduction of coinage, a scale and a piece of bronze were still used as a symbol of the sale and the change of ownership in the ceremony of mancipatio, by which the transfer of certain types of goods, like land, for example, was officially confirmed.
In the late fourth century BC, silver coins were minted for Rome in Naples. Their origin and function are discussed by specialists. Their impact on the Roman economy was surely limited. Only at the beginning of the third century BC, Rome began to standardize the form of bronze bars by introducing the use of cast ingots. The purpose of this change was probably to achieve a more uniform set of weights and to facilitate trade. The new bars were marked with various motives, and this is why they are commonly known today as aes signatum.
signatum aes (Crawford RRC 5 / 1)
The oldest bars had a motive only on one side, but the Romans began soon to decorate both major faces. The motives served, probably, as a certification of the characteristics of the piece. By covering also the entire length of the block, they allowed to recognize if it was intact or if a portion had been removed.
Of course, these bars cannot be considered as coins in the strict sense, because they were produced by pouring molten metal into molds. They met, however, a monetary function as means of exchange. It was common practice to split them when a piece of lesser value was needed.
signatum aes (Crawford RRC 9 / 1)
The motives of these ingots are not without a certain beauty, as seen in the examples that accompany this text. The two most elaborate are RRC 5 / 1 (Crawford) with a bull on each side and RRC 9 / 1 (Crawford) that presents both an elephant and a wild boar. These are usually related to a story told by Aelianus Tacticus, according to which the Romans used pigs to scare the elephants used against them in the Pyrrhic wars.