Constantine I Follis. 6.39 gr; 28.39 mm. 307 AD. 

Obv: FL VAL CONSTANTINVS NOB C, laureate & cuirassed bust right 
Rev: MARTI PATRI PROPVGNATORI, Mars, helmeted, advancing right, chlamys 
 flying out behind him, holding transverse spear & shield; PLN in ex. 

RIC VI London, 96 var (listed in RIC only for Maximian), rare. 
Three are known to exist.

Contributed by Dane for TimeLine Originals, December, 2008.
Now in the collection of Lee Toone.