Licinius' fleet of 350 ships was defeated by Constantine I's fleet in 323. 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 170,000 men at the Battle of Adrianople (July 3, 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 (September 18), resulted in Licinius' final submission. While Licinius' co-emperor Sextus Martinianus was killed, Licinius himself was spared due to the pleas of his wife, Constantine's sister, and interned at Thessalonica. The next year, Constantine had him killed, accusing him of conspiring to raise troops among the barbarians.