Histamenon was the name given to the gold Byzantine solidus when the slightly lighter tetarteron was introduced in the 960s. To distinguish the two, the histamenon was changed in form from the origina
Histamenon of Emperor Constantine VIII (r. 1025–1028)
Histamenon of Emperor Isaac I Komnenos (r. 1057–1059), with its by then characteristic concave form
An example of the greatly debased later histamena: an electrum coin of the first years of Emperor Alexios I Komnenos (r. 1081–1118).
The solidus or nomisma 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
Histamenon
…Histamenon (Greek: ἱστάμενον [νόμισμα], histámenon [nómisma] lit. 'standard coin') was the name given to the gold Byzantine solidus when the slightly lighter tetarteron was introduced in the 960s. To distinguish the two, the histamenon was changed in form from the original solidus…
Solidus of Theodosius II, minted in Constantinople c. 435. This design of the emperor with the spear over his shoulder was the conventional portrait for over a century in the Eastern Roman Empire, from AD 395 to 537
Solidus of Constantine the Great, minted in AD 324 or 325
Solidus of Constantius II from Antioch, 347–355. A holed coin such as this was likely worn as a jewelry piece by a prominent or wealthy Roman
Light-weight solidus of 22 siliquae minted by emperor Tiberius Constantine at Antioch in Syria, c. 580. The light-weight solidi were minted from c. 550–650 and were primarily used for foreign trade with Europe.