History · Article
Byzantine Coinage
The Byzantine gold solidus held its weight and purity for seven hundred years and was accepted from Britain to China. The denominations, the mints, the debasement of the 11th century and the reform of 1092.
A sixth-century Egyptian merchant named Kosmas Indikopleustes, who had travelled to India and Ceylon, recorded a conversation in which a local king was shown a Byzantine gold coin and a Persian silver one, and acknowledged that the Roman coin was the finer. Kosmas tells the story to prove the superiority of the Christian empire, which is not evidence of much. What the anecdote does show is that a coin struck in Constantinople was recognisable and respected on the far side of the Indian Ocean.
The Byzantine gold coin was the most stable currency in recorded history. Introduced by Constantine around 309, it kept its weight — 1/72 of a Roman pound, about 4.5 grams — and a purity above 95 per cent for roughly seven hundred years. No other currency has managed anything comparable.
The Denominations
Gold. The solidus, in Greek the nomisma. Fractions: the semissis (half) and tremissis (third). This was the money of taxation, salaries, international trade and diplomacy.
Silver. Less important in the Byzantine system than in the Roman or western medieval ones. The miliaresion, introduced in its lasting form in the eighth century, was reckoned at 12 to the nomisma. The hexagram, a heavier silver piece, was struck under Heraclius as an emergency wartime issue.
Copper. The follis was the coin ordinary people used. Anastasius I reformed the copper coinage in 498, introducing large pieces marked with their value in Greek numerals — M for 40 nummi, K for 20, I for 10, E for 5 — a piece of practical design that made small transactions workable and is one of the reasons his reign is a conventional starting point for “Byzantine” as opposed to “late Roman” history.
The exchange rate between gold and copper varied, but a nomisma was worth in the region of 288 folles in the sixth century.
What Things Cost
Approximate figures from various periods, to be treated as indicative rather than precise:
| Annual wage, unskilled labourer | 6–12 nomismata |
| Annual pay, ordinary soldier (10th c.) | About 12 nomismata |
| A modest house in a provincial town | 10–30 nomismata |
| A horse | 12–20 nomismata |
| A slave | 20–30 nomismata |
| Senior court title’s annual stipend | Hundreds to thousands |
The Book of the Eparch, described in its own article, gives margins and commissions in these units and is the best source for relative prices.
The Iconography
Byzantine coins are a continuous political and religious statement, and the changes in what appears on them track the empire’s history closely.
Early. Emperor in profile or three-quarter bust on the obverse; a Victory, a cross, or the personification of Constantinople on the reverse.
From Justinian II (685–695). The first image of Christ on a coin, with the emperor on the reverse styling himself servus Christi, servant of Christ. This is a theological claim in metal: the emperor is subordinate to a higher ruler.
During iconoclasm. Christ disappears from the coinage, replaced by portraits of the emperor and his co-rulers and by crosses — the numismatic evidence for imperial religious policy is direct and datable, and it is one of the better sources for the chronology of the controversy.
After 843. Christ returns and stays. From the tenth century the Virgin appears, and from the eleventh the emperor is regularly shown being crowned by Christ or the Theotokos.
Later. The coins become thin, concave (scyphate, cup-shaped) from the eleventh century, and by the Palaiologan period crude in execution — a decline visible to the naked eye.
Mints
The early empire operated mints across the Mediterranean: Constantinople, Thessalonica, Nicomedia, Cyzicus, Antioch, Alexandria, Carthage, Ravenna, Rome, Syracuse, Cherson. The losses of the seventh century closed most of them, and by the middle Byzantine period Constantinople was effectively the only mint of consequence, with Thessalonica and one or two others operating intermittently.
Mint marks and officina numbers on the coins allow issues to be attributed precisely, and the disappearance of a mint from the record is a useful indicator of when a province was actually lost.
The Debasement
The gold standard broke in the eleventh century. From about 1030 the fineness of the nomisma began to fall, gradually at first and then sharply: by the 1080s the coin contained perhaps a tenth of its former gold.
The causes are argued. A fiscal crisis from declining revenue and rising military expenditure is the general explanation; some historians have suggested a deliberate monetary expansion to stimulate a growing economy, which would make it a policy rather than a failure. Either way, the consequences were severe: contracts and taxes had to be renegotiated, confidence collapsed, and the state’s principal instrument of diplomacy — a coin everyone would take — lost its value.
The Reform of 1092
Alexios I Komnenos rebuilt the system with a new set of denominations:
- The hyperpyron, a gold coin of about 20.5 carats — lower than the old solidus but stable and reliable
- The aspron trachy, an electrum (gold-silver alloy) piece
- Billon and copper trachea for small change
The reform worked. The hyperpyron held for roughly a century and became the standard unit of Mediterranean accounting once again.
Its decline resumed in the thirteenth century, and by the fourteenth the Byzantine gold coinage had ceased to be internationally significant. Venetian ducats and Florentine florins — themselves deliberately struck to the standard of the old Byzantine coin — took over the role, and Byzantine merchants used them.
Coins as Evidence
Numismatics does more work in Byzantine history than in most fields, because the documentary record is thin.
Coin finds date archaeological layers, map the circulation of money and therefore the vitality of a regional economy, and indicate the reach of the state. The disappearance of copper coinage from provincial sites in the seventh century is one of the principal arguments for the contraction of urban life; its reappearance in the ninth is one of the principal arguments for recovery.
Byzantine gold also turns up far outside the empire: in Scandinavian hoards, deposited by returning Varangians; in Anglo-Saxon England; in India; and in Chinese tombs of the Tang period, where solidi and local imitations have been excavated. Those finds are the physical trace of a coin that functioned, for several centuries, as the reserve currency of the Old World.
Reading a Byzantine Coin
A short guide to what the marks mean turns a coin from an object into a document.
Obverse. Usually the emperor, in bust or standing, with regalia — crown with pendilia, loros or chlamys, globus cruciger, labarum or sceptre. From Justinian II, often Christ instead, with the emperor moved to the reverse. Co-emperors appear alongside, which dates an issue to the years of a specific joint reign.
Legend. Latin in the early period, Greek from the seventh and eighth centuries, frequently abbreviated and often blundered by die-cutters who did not read it.
Reverse. A cross on steps, a Victory, a value mark on copper, or an inscription. The formula Rex Regnantium — king of those who rule — appears with images of Christ, making the theological claim that the emperor’s authority is delegated.
Mint mark. CON for Constantinople, THES for Thessalonica, RAV for Ravenna, CAR for Carthage, and so on, usually in the exergue below the design.
Officina number. A Greek letter indicating which workshop within the mint struck it, which allows the reconstruction of mint organisation.
Regnal year. On copper of the sixth and seventh centuries, marked ANNO with a numeral — a genuinely useful feature, since it dates a coin to a single year.
A follis of Justinian, then, can be read as: Constantinople mint, third workshop, year twelve of the reign, worth forty nummi. Few medieval objects are that informative.
The Solidus Abroad
The coin’s international career is documented archaeologically and is worth setting out, because it is the best single measure of Byzantine economic reach.
Scandinavia. Byzantine gold and silver in Swedish and Gotland hoards, deposited between the ninth and eleventh centuries, matching the Varangian service recorded on the runestones.
Britain and Ireland. Individual finds from the sixth and seventh centuries, including the Sutton Hoo burial, which contained Merovingian gold but reflects the same Mediterranean-facing exchange system.
India and Sri Lanka. Solidi and imitations found at trading sites on both coasts, consistent with the account of Kosmas Indikopleustes.
China. Byzantine gold coins and local imitations excavated from Tang-period tombs in Shaanxi, Xinjiang and elsewhere — dozens of examples, several pierced for wear as ornaments, arriving along the overland routes.
The Islamic world. The first Umayyad gold coinage imitated the solidus directly, with the emperor’s figure replaced by the standing caliph, before Abd al-Malik’s reform of 696–697 introduced a purely epigraphic coinage. That reform was itself a statement of independence from a monetary system everyone had been using.
A coin struck in Constantinople and buried in a Tang tomb or a Gotland field is the physical evidence for a monetary system whose reach exceeded the empire’s political one by several thousand miles.
The Debasement in Numbers
Putting figures on the eleventh-century collapse shows why it mattered so much.
| Reign | Approximate gold content of the nomisma |
|---|---|
| To c. 1030 | c. 24 carats (near pure) |
| Michael IV (1034–41) | c. 23 carats |
| Constantine IX (1042–55) | c. 21 carats |
| Constantine X (1059–67) | c. 18 carats |
| Romanos IV (1068–71) | c. 16 carats |
| Michael VII (1071–78) | c. 12 carats |
| Nikephoros III (1078–81) | c. 8 carats |
| Alexios I, before reform | c. 3 carats |
A coin that had held its standard for seven centuries lost seven-eighths of its gold in fifty years.
The practical consequences were immediate and severe. Tax assessments fixed in nomismata could be paid in debased coin, so real revenue collapsed even as nominal revenue held. Contracts became unenforceable. Foreign creditors and mercenaries refused payment in the new coin. And the empire lost the instrument that had underwritten its diplomacy for centuries — a coin everyone would take without weighing.
Alexios I’s reform of 1092 rebuilt the system around the hyperpyron at about 20.5 carats, and it held for roughly a century. But the restored coin was never the old solidus, and the reputation, once lost, did not return.
- The Byzantine Economy — taxation, trade and the fiscal system
- The Book of the Eparch — prices and margins in practice
- Byzantine Diplomacy — gold as an instrument of policy
- Constantine the Great — who created the solidus
- The Varangian Guard — how Byzantine gold reached Sweden
- Byzantine Enamel and Metalwork — the goldsmith’s other work
- Byzantine Iconoclasm — the controversy visible on the coins