Constantine II AE Follis. 327-328 AD. 

Obv: CONSTANTINVS IVN NOB C, laureate, draped bust left holding Victory and mappa
Rev: PROVIDEN-TIAE CAESS, campgate, 2 turrets, 6 layers, star above, no doors, dot PTRE in ex. 

RIC VII Trier 513. Of the highest rarity (R5)

With permission of Roma Numismatics, June 2009