Constantine I AE3. 

Obv: CONSTAN-TINVS AVG, diademed head right with square-shaped rosettes 
Rev: PROVIDEN-TIAE AVGG, campgate, 2 turrets, 9 layers, star above, no doors. 
Mintmark: SMANTB. 

RIC VII Antioch 78, rated R4.

Contributed by Dane for George Clegg (biggyg2), October 2007