Debasement in the context of "Year of the Six Emperors"

The Crisis of the Third Century, also known as the Military Anarchy or the Imperial Crisis, was a period in Roman history during which the Roman Empire nearly collapsed under the combined pressure of repeated foreign invasions, civil wars and economic disintegration. At the height of the crisis, the Roman state split into three distinct and competing polities. The period is usually dated between the death of Severus Alexander (235) and accession of Diocletian (284).

The crisis began in 235 with the assassination of Emperor Severus Alexander by his own troops. During the following years, the empire saw barbarian invasions and migrations into Roman territory, civil wars, peasant rebellions and political instability, with multiple usurpers competing for power. This led to the debasement of currency and a breakdown in both trade networks and economic productivity, with the Plague of Cyprian contributing to the disorder. Roman armies became more reliant over time on the growing influence of the barbarian mercenaries known as foederati. Roman commanders in the field, although nominally loyal to the state, became increasingly independent of Rome's central authority.

The antoninianus or pre-reform radiate was a coin used during the Roman Empire thought to have been valued at 2 denarii. It was initially silver, but was slowly debased to bronze with a minimal silver content. The coin was introduced by Caracalla in early 215 AD. It was silver, similar to the denarius, except that it was slightly larger and featured the emperor wearing a radiate crown, indicating it was a double denomination. Antoniniani depicting women (usually the emperor's wife) featured the bust resting upon a crescent moon.

Even at its introduction, the silver content of the antoninianus was only equal to 1.5 denarii. This created inflation: people rapidly hoarded the denarii (Gresham's law), while both buyers and sellers recognized the new coin had a lower intrinsic value and elevated their prices to compensate. Silver bullion supplies began running short because the Roman Empire was no longer conquering new territory, the Iberian silver mines had been exhausted, and a series of soldier emperors and usurpers needed coin to pay their troops and buy their loyalty. Each new issue of the antoninianus thus had less silver in it than the last, and thus contributed to ever-increasing inflation.

The solidus (Latin 'solid'; pl.: solidi) or nomisma (Greek: νόμισμα, romanized: nómisma, lit. 'coin') was a highly pure gold coin issued in the Later Roman Empire and Byzantine Empire. It was introduced in the early 4th century, replacing the aureus, and its weight of about 4.45 grams remained relatively constant for seven centuries.

In the Byzantine Empire, the solidus or nomisma remained a highly pure gold coin until the 11th century, when several Byzantine emperors began to strike the coin with less and less gold. The nomisma was finally abolished by Alexios I Komnenos in 1092, who replaced it with the hyperpyron, which also came to be known as a "bezant". The Byzantine solidus also inspired the zolotnik in the Kievan Rus' and the originally slightly less pure gold dinar first issued by the Umayyad Caliphate beginning in 697.

In economics, Gresham's law is a monetary principle stating that "bad money drives out good". For example, if there are two coins in circulation containing metal of different value, which are accepted by law as having similar face value, the more valuable coin based on the inherent value of its component metals will gradually disappear from circulation.

The law was named in 1857 by economist Henry Dunning Macleod after Sir Thomas Gresham (1519–1579), an English financier during the Tudor dynasty. Gresham had urged Queen Elizabeth to restore confidence in the then-debased English currency.

In macroeconomics, hard currency, safe-haven currency, or strong currency is any globally traded currency that serves as a reliable and stable store of value. Factors contributing to a currency's hard status might include the stability and reliability of the respective state's legal and bureaucratic institutions, level of corruption, long-term stability of its purchasing power, the associated country's political and fiscal condition and outlook, and the policy posture of the issuing central bank.

Safe haven currency is defined as a currency which behaves like a hedge for a reference portfolio of risky assets conditional on movements in global risk aversion. Conversely, a weak or soft currency is one which is expected to fluctuate erratically or depreciate against other currencies. Softness is typically the result of weak legal institutions and/or political or fiscal instability. Junk currency is even less trusted than soft currency, and has a very low currency value. Soft and junk currencies often suffer sharp falls in value.