Martinian

Martinian (Latin: Martinianus; died spring 325) was Roman emperor from July to 18 September 324. He was raised to the purple by the emperor Licinius, whom he had hitherto served as a senior bureaucrat, during Licinius's civil war against the emperor Constantine I. Constantine defeated both emperors and forced them to abdicate, and executed them after initially showing leniency.

Source: Wikipedia — https://en.wikipedia.org/wiki/Martinian_(emperor)