Martius Martinianus was a leading general under Licinus I prior to the final showdown between Licinius and Constantine in 324 AD. As fate would have it, the two armies of Constantine and Licinius met at Hadrianopolis on July 3rd. Constantine won a major victory and Licinius fled across the Bosphorus along with Martinianus.
Once in the Bosphorus, Licinius raised Martinianus to the rank of co-Augustus. It was intended that Martinianus would replace Constantine when victory would be theirs in the next confrontation. That would come sooner than expected. Constantine ferried his own troops across the Bosphorus and confronted Licinius and Martinianus at Chrysopolis on 18 September, 324 AD. A few days later, both Licinius and Martinianus surrendered to Constantine at Nicomedia on the understanding that their lives would be spared. When it came to matters of politics, however, Constantine was not a man to be trusted. He broke his word, as usual, and had Licinius hanged at Thessalonica along with his son Licinius II. Martinianus was also murdered on the orders of Constantine at Cappadocia.
The extremely rare coinage struck by Martinianus is only known in a single denomination. His reign was short, between late July and mid September of 324 AD. It is unlikely that any other denominations were struck since he was a junior partner with Licinius I.
Mints: Cyzicus, Nicomedia
D N M MARTINIANVS P F AVG