Uncertain Byzantine Follis, Mint error, Incuse Obverse

Constantine I, AE Follis (bronze, 6g, 22mm), Mint error, Incuse Obverse plain field, Costantinople (?) mint

Obv: Incuse obverse, plain field

Rev: Large M; cross above, A/N/N/O-X/X (?) (date) flanking, B below; CON (?)

Ref: Unprecedented mint error

Note: An intriguing and apparently unpublished mint error issue of Constantine I. The obverse is entirely incuse and devoid of design, likely resulting from a major striking anomaly, while the reverse displays a large "M" denomination mark with traces of the mint signature below. Such dramatic errors are exceptionally rare in the Byzantine and late Roman series, making this specimen a remarkable example of an unusual minting mishap and of considerable numismatic interest.