Justinian I (527-565) AE Follis (Bronze, 21.17g, 42mm) Nicomedia Dated RY 13 (539/40).
Obv: Helmeted and cuirassed bust facing, holding globus cruciger and shield; cross to right
Rev: Large M; cross above, A/N/N/O X/II/I across field; B//NIK.
Ref: Sear 201.