on the plains in the Battle of Mardia (also known as the Battle of Campus Ardiensis) in Thrace. The emperors were reconciled after these two battles and Licinius had his co-emperor Valens killed. Over the next ten years, the two imperial colleagues maintained an uneasy truce. Licinius kept himself busy with a campaign against the Sarmatians in 318, but temperatures rose again in 321 when Constantine pursued some Sarmatians, who had been ravaging some territory in his realm, across the Danube into what was technically Licinius's territory. When he repeated this with another invasion, this time by the Goths who were pillaging Thrace under their leader Rausimod, Licinius complained that Constantine had broken the treaty between them. Constantine wasted no time going on the offensive. Licinius's fleet of 350 ships was defeated by Constantine's fleet in 323. Then in 324, Constantine, tempted by the "advanced age and unpopular vices" of his colleague, again declared war against him and having defeated his army of 165,000 men at the Battle of Adrianople (3 July 324), succeeded in shutting him up within the walls of Byzantium. The defeat of the superior fleet of Licinius in the Battle of the Hellespont by Crispus, Constantine's eldest son and Caesar, compelled his withdrawal to Bithynia, where a last stand was made; the Battle of Chrysopolis, near Chalcedon (18 September), resulted in Licinius' final submission. In this conflict Licinius was supported by the Gothic prince Alica. Due to the intervention of Flavia Julia Constantia, Constantine's sister and also Licinius' wife, both Licinius and his co-emperor Martinian were initially spared, Licinius being imprisoned in Thessalonica, Martinian in Cappadocia; however, both former emperors were subsequently executed. After his defeat, Licinius attempted to regain power with Gothic support, but his plans were exposed, and he was sentenced to death. While attempting to flee to the Goths, Licinius was apprehended at Thessalonica. Constantine had him hanged, accusing him of conspiring to raise troops among the barbarians. Character and legacy As part of Constantine's attempts to decrease Licinius's popularity, he actively portrayed his brother-in-law as a pagan supporter. This may not have been the case; contemporary evidence tends to suggest that he was at least a committed supporter of Christians at one point. He co-authored the Edict of Milan which ended the Great Persecution, and re-affirmed the rights of Christians in his half of the empire. He also added the Christian symbol