Constantine I or II (my rough guess from the bust on the obv.), nummus, AE? I've not really seen a reverse with 3 soldiers? (it seems like), or maybe a captive between two soldiers? the types I most commonly see is with 2 standards between two soldiers…
I am more experienced in the field of ancient and chinese coins, south-east asian coins included too!
I use Van Meter and yours looks like Honorius AE3. The large diadem helps here. The reverse is GLORIA ROMANORUM and has three emperors on the back, two holding shields. A moderately hard to find one.