Constantine I, 307/310-337. Follis (Bronze, 20 mm, 2.30 g), uniface mint error, Siscia, 318. IMP CONSTANTINVS AVG Helmeted and cuirassed bust of Constantine I to left, holding spear over right shoulder and decorated shield in his left hand. Rev. Blank. Cf. RIC 51 (for possible prototype). Struck somewhat off center, otherwise, very fine.

This uniface mint error probably resulted from an unstruck second flan being stuck in between the coin and the reverse die