Coin types related to retirement types of the Roman emperors Diocletian and Maximian. 

Galerius
Follis. Silvered. 26 mm. 9.04 grams.
GAL VAL MAXIMIANVS NOB CAES
Laureate head right.
IOVI CO-NS CAES

Jupiter standing left holding Victory on globe and long staff, with cloak over his left shoulder.

ALE in exergue.
RIC VI Alexandria 43. Struck c. 304-5. 

Galerius was Caesar in the East where Diocletian had Jupiter as his patron god.

Maxentius
CONSERVATORES KART SVAE
[See the type for Maximian on the abdication page.]

Carthage

Maxentius
 

CONSERVATORES AFRICAE SVAE

[See the type for Maximian on the abdication page.]

Constantine 


 

Maxentius
Ticinum

Maximinus II
25 mm. 6.28 grams.
S  A
PTR  in exergue
RIC Trier 720a "c. summer 307"