Roman as–denarius–sestertius accounting

The story

This history covers a connected Roman accounting system, not just a single coin. The denarius appeared around 211 BC at ten asses, while the sestertius represented two and a half asses. Retariffing around 141 BC changed those values to sixteen and four asses respectively, preserving four sestertii to the denarius. The appearance of the denarius did not create Roman accounting from nothing. ^{[4] [1]}

New coin types did not automatically replace the account unit. Caracalla introduced the antoninianus in AD 215; it is generally interpreted as a double denarius, although the tariff is inferred and debated. In AD 301 the Aphrodisias monetary dossier still valued the argenteus and nummus in denarii and regulated the settlement of debts. ^{[5] [2]}

Denarius reckoning continued alongside gold accounts in late antiquity. Egyptian evidence around the turn of the fourth and fifth centuries records myriads of denarii beside solidi. The shift toward gold accounting therefore has no single universal denarius-to-solidus conversion or ending date. Coin manufacture and the life of an accounting unit are different histories. ^{[3] [6] [7]}