A Buyer’s Guide to Byzantine Gold Solidi

For seven centuries the gold solidus was the most trusted coin in the Mediterranean world. Merchants from Britain to India accepted it, and its weight and purity barely changed from Constantine the Great to the eleventh century. For collectors, Byzantine solidi offer something rare: high-purity gold, imperial portraits and a direct line to the history of Constantinople, often in remarkable condition.

A coin that held its value for 700 years

Constantine I introduced the solidus in the early fourth century, struck at 72 to the Roman pound, about 4.5 grams of nearly pure gold. His successors kept that standard. The coin we now call Byzantine is the same solidus, carried on by the emperors in Constantinople after the West fell.

The standard finally slipped in the eleventh century, when the gold content was progressively reduced. Alexios I Komnenos replaced the old coin with a new one, the hyperpyron, in 1092.

How to read a solidus

• Obverse: the emperor, at first in a three-quarter helmeted bust holding spear and shield, later facing forward with globus cruciger, crown and imperial robes.
• Reverse: early coins show Victory or an angel holding a cross; from the seventh century, the cross on steps dominates.
• VICTORIA AVGG and a letter: the final letter on the reverse, from A to I, is the officina, the workshop within the mint that struck the coin. Some officinae are much scarcer than others, which matters to specialists.
• CONOB in the exergue: the mint signature, usually read as “Constantinople, pure gold”. Coins struck at other mints such as Thessalonica, Ravenna or Carthage are often scarcer.

Landmark types worth knowing

• Justinian I (527–565). The great builder of Hagia Sophia, with the facing helmeted bust. See our Justinian I solidus from Thessalonica.
• Justin II (565–578). Introduced the seated figure of Constantinopolis on the reverse. See our Justin II solidus.
• Heraclius (610–641). Famous for solidi showing the emperor with his sons, standing side by side.
• Justinian II (685–695, 705–711). In his first reign he became the first emperor to put the face of Christ on a coin, moving his own portrait to the reverse. Earlier coins of the same reign carry the traditional imperial bust, like our Justinian II first-reign solidus.
• Leontius (695–698). The general who overthrew Justinian II and cut off his nose. His solidi, with a striking facing bust, are scarce. See our Leontius solidus.
• After Iconoclasm (from 843). The image of Christ returns, and Middle Byzantine solidi typically show Christ on the obverse and the emperor on the reverse.

What to check before you buy

• Weight. A full-weight solidus is close to 4.4–4.5 g. Lighter coins exist officially (marked lightweight issues), but an unexplained low weight is a warning sign.
• Mount and repair marks. Solidi were often worn as jewelry. Look for traces of a removed loop, edge filing, tool marks in the fields or a slight bend. These reduce value even on an attractive coin.
• Strike and centering. Gold rarely corrodes, so condition is mostly about strike, wear and handling. A sharp, well-centered portrait is what drives value.
• Clipping and graffiti. Ancient clipping or scratched marks are part of a coin’s history but should be described.
• Authenticity. Gold attracts forgers. Buy from a seller who guarantees authenticity, and read our guide to spotting fakes.

Starting a collection

Common sixth- and seventh-century types, such as solidi of Justinian I, Maurice Tiberius, Phocas and Heraclius, are the usual starting point and are available in high grades. From there, collectors move toward scarcer emperors, rare officinae and provincial mints. Late Roman solidi, from Constantine’s dynasty to the fall of the West, make a natural companion set. See our Roman gold.

Browse the full selection in our Byzantine collection, or contact us for help choosing a first solidus.