Constantine I, AE follis, Ticinum. AD 312-313.

CONSTANTINVS PF AVG, laureate, cuirassed bust right.
MARTI CONSERVATORI, Mars, helmeted and in military dress, standing left, holding Victory on globe and spear, shield at his side.

Mintmark PT.

RIC VI Ticinum 121.
Rated rare.

Offered as an "unpublished" coin on ebay by a German seller for $1,500 (!), Feb. 2024.