On 30 April 313, the two armies clashed at theBattle of Tzirallum, and in the ensuing battle Daza's forces were crushed. The war between them ended only with Daza's death in August 313. bThe defeat of the superior fleet of Licinius in theBattle of the Hellespont byCrispus, Constantine's eldest son andCaesar, compelled his withdrawal toBithynia, where a last stand was made; theBattle of Chrysopolis, nearChalcedon (18 September), resulted in Licinius' final submission.