324 spring-summer Constantine prepares and begins the campaign against Licinius from Thessalonica.
324 July 3 Battle of Adrianople.
324 July-September Battle of Chrysopolis.
324 September 19 Licinius surrenders to Constantine at Nicomedia.
324 November 8 Constantine founds Constantinople; Constantius (II) proclaimed Caesar; this may be when Helena and Fausta are proclaimed Augustae.
3 July: Constantine defeats Licinius at Adrianople.
18 September: Constantine defeats Licinius a second time at Chrysopolis; Licinius survives and retreats to Nicomedia and surrenders soon thereafter. Constantine enters Nicomedia in triumph.
Constantine becomes sole Augustus of the Roman Empire.
Autumn: Constantine issues a letter to all his provincials whereby Christianity becomes the favored religion of the whole empire.
8 November: Fausta and Helena are granted the rank of Augusta.