Here’s a fairly early issue for Constantine from the London mint with a recently dug up patina.
Constantine I
A.D. 310
25mm 3.8gm
IMP CONSTANTINVS P [F] AVG; laureate and cuirassed bust right.
MARTI CONSERVATORI; Mars in military dress, stg. r., reversed spear in r. hand, l. on shield set on the ground; T-F across fields.
in ex. PLN
RIC VI London 119