Battle of the Hellespont

The Battle of the Hellespont, consisting of two separate naval clashes, was fought in 324 between a Constantinian fleet, led by the eldest son of Constantine I, Crispus; and a larger fleet under Licinius' admiral, Abantus . Despite being outnumbered, Crispus won a very complete victory.

Following his defeat at Adrianople, in Thrace, Licinius and his main army fell back to the city of Byzantium. Licinius left a strong garrison in Byzantium but ferried the greater part of his troops across the Bosphorus to the Asian shore. To maintain his force in Byzantium, and to secure his line of communication between Asia Minor and the city, retaining control of the narrow waters separating Thrace from Bithynia and Mysia now became imperative for Licinius. Constantine, if he wished to cross to Asia in order to destroy Licinius' means of further resistance, had to gain control of the sea crossings. Licinius' main army was on the Bosphoros to cover this crossing point whilst the bulk of his navy was moved to cover the Hellespontine narrows. He also assembled a second military force, under his newly elevated co-emperor Martinian, at Lampsacus on the Asian shore of the Hellespont.

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