Byzantine Folles 101

The Byzantine follis is one of the most beginner-friendly ancient coins there is: large, boldly designed, historically rich, and cheap. The reform of Anastasius I in 498 created a clear system of marked bronze denominations, and the follis — the 40-nummi piece — is the big one, often the size of a modern crown. Its reverse carries a giant letter M (the Greek numeral for 40), which makes the whole series instantly recognisable on a dealer's tray.

Reading the reverse

Byzantine bronze tells you its own value. The big mark of value is a letter: M for the follis (40 nummi), K for the half-follis (20), I for the decanummium (10), and E for the pentanummium (5). Around and beside it you will often find a mint mark in the exergue (CON for Constantinople, NIKO for Nicomedia, THEUP for Antioch/Theoupolis) and an officina letter. Once you can read the value mark and the mint, you can attribute most Byzantine bronze without a reference.

• M — follis, 40 nummi (the large coin).
• K — half-follis, 20 nummi.
• I — decanummium, 10 nummi.
• E — pentanummium, 5 nummi.

Coins you can date

Here is the feature collectors love: from Justinian I onward, many folles carry a regnal year. Look for ANNO (Latin for 'in the year') beside the M, with a Roman or Greek numeral giving the year of the emperor's reign — so 'ANNO XIII' means the thirteenth year. Combined with the known accession dates, this lets you pin many folles to an exact year, something almost no other ancient coin offers. It turns attribution into a small, satisfying puzzle.

Where to start

Justinian I (527–565) is the natural entry point: his reign produced large, handsome dated folles in quantity, especially the big module coins of the Nicomedia and Cyzicus mints. From there, collectors branch out to the dramatic facing-bust folles of the later period, the heavy issues of Justin II, or the chaotic, often crude bronze of the seventh-century crisis. Buy coins with a clear M, a legible date if you can find one, and a smooth patina — and you will have history you can read for very little money.