Flavius Galerius Valerius Licinianus Licinius (c. 250 - 325) was Roman emperor from 308 AD to 324 AD.
Licinius went with his close friend the Emperor Galerius on the Persian expedition in 297. After the death of Flavius Valerius Severus, Galerius declared Licinius emperor honorific in the West in 308.
On the death of Galerius, in May 311, Licinius shared the entire empire with Maximinus Daia. The Hellespont and the Bosporus were the dividing line.
In 313 he married Flavia Julia Constantia, half-sister of Constantine, at Mediolanum (now Milan). Together with Constantine he issued the "Edict of Milan" that allowed Christianity to be professed in the empire.
On April 30, Licinius won against Maximinus at the Battle of Tzirallum. So he became master of the East, while his brother-in-law, Constantine, was master in the West.
In 314, a civil war began between Licinius and Constantine. Constantine won at Cibalae in Pannonia and again 2 years later in Thrace. Then followed a period during which they worked together. But in 324 Constantine attacked him again and Licinius had to give up. Because his wife, Constantine's sister, asked for his survival he was not killed immediately. In 325 Constantine accused him of starting a conspiracy with the barbarians and had him killed.
References
Other websites
Socrates Scholasticus account of Licinius' end
