Constantine II AE20. 318-320 AD. 

Obv. DN FL CL CONSTANTINVS NOB C, laureate and draped bust left 
holding globe, sceptre and mappa
Rev. PROVIDEN-TIAE CAESS, campgate, 3 turrets, 6 layers, no star, 
no doors, dot over dot in right field

Mintmark SMHA. 

RIC VII Heraclea 37 var (unlisted officina).

Dane's collection, June 2009.