Double sestertius

The double sestertius was a large Roman coin made of

orichalcum Orichalcum or aurichalcum is a metal mentioned in several ancient writings, including the story of Atlantis in the '' Critias'' of Plato. Within the dialogue, Critias (460–403 BC) claims that orichalcum had been considered second only to g ...

(

brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wi ...

) first issued by

Trajan Decius Gaius Messius Quintus Traianus Decius ( 201 ADJune 251 AD), sometimes translated as Trajan Decius or Decius, was the emperor of the Roman Empire from 249 to 251. A distinguished politician during the reign of Philip the Arab, Decius was procla ...

in AD 249–251, as a response to the

inflation In economics, inflation is an increase in the general price level of goods and services in an economy. When the general price level rises, each unit of currency buys fewer goods and services; consequently, inflation corresponds to a reduct ...

ary pressures of the time which had devalued the buying power of the conventional

sestertius The ''sestertius'' (plural ''sestertii''), or sesterce (plural sesterces), was an ancient Roman coin. During the Roman Republic it was a small, silver coin issued only on rare occasions. During the Roman Empire it was a large brass coin. The ...

. In reality the new coin was little bigger than the traditional sestertius, which by then was being manufactured at a lower weight and smaller size than it had originally been, and was not a success. The new coin fell out of use but was revived by the rebel emperor

Postumus Marcus Cassianius Latinius Postumus was a Roman commander of Batavian origin, who ruled as Emperor of the splinter state of the Roman Empire known to modern historians as the Gallic Empire. The Roman army in Gaul threw off its allegiance to Ga ...

(259–268), who ruled a breakaway empire consisting of Britain, Gaul and parts of Germany, and was keen to associate his regime with a reformed coinage system. Postumus issued his own version of the double sestertius, often taking very worn old sestertii and using these to overstrike his own portrait and legends on, probably because of a shortage of metal. After his reign, the Roman coinage system degenerated further with almost the only circulating pieces being very debased double-denarius coins, known to us as '' antoniniani'' or 'radiates' (from the use of the

radiate crown A radiant or radiate crown, also known as a solar crown, sun crown, Eastern crown, or tyrant's crown, is a crown, wreath, diadem, or other headgear symbolizing the sun or more generally powers associated with the sun. Apart from the Ancient ...

). Older coins like the

soon dropped entirely out of use, with many being melted down to create new radiates. By the fourth century AD even these had been discontinued and an entirely new coinage system had been created. {{Roman coinage Coins of ancient Rome