Roman Empire. Constantine I (The Great), 306-337 AD. AE Follis. Bust Of Sol. Mint Of Trier, 310-313 AD.
 
Obv: CONSTANTINVS P F AVG, laureate and cuirassed bust right. Rev: SOLI INVICTO COMITI, radiate and draped bust of Sol right.
 
A rich and attractive tone, a nice example of this double-headed issue.