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.