Constantine I   306-337  A.D.

Coin Description Constantine I The Great, AE 20mm, Grade EF , silvered bronze the silvering is almost completely intact, this coin was bought from Forvm, I've got another example of this coin in my collection yet they are completely different, VM 85, RBC 282, RIC VII Heraclea 16
Obverse The portrait is of Constantine the Great a laureate bust wearing consular robes facing left and holding a mappa in his right and globe (symbolizing the world/empire he rules) and scepter in his left hand. The legend reads IMP CONSTANTINVS AVG meaning: IMP (Imperator = the Emperor / supreme military commander) CONSTANTINVS (his name) AVG Augustus which defines him as being the emperor. The legend is broken which is a sign of the highest respect and signifies him as the senior Augustus
Reverse

The reverse shows a campgate (watchtower) with three signal beacons. The legend reads PROVIDENTIAE AVGG which translates as "The foresight of the emperors". The second G in AVGG means that there is another legitimate ruler with the title of Augustus, in this case Licinius. For a bit more on Providentia see here.

Mint The exergue reads MHTβ meaning Moneta Heraclea Thrace and the 2nd workshop (Beta) of Heraclea (Heraclea Thrace being the full name of Heraclea).
The Entire Story The entire story of this coin would read: Our supreme commander Constantine the Great Augustus. The foresight of the emperors in combination with the campgate might show that the emperors are building extra defenses for the future defense of the empire.