Byzantine ships

thumb|right|250px|Illustration from the Madrid Skylitzes showing the Byzantine fleet repelling the Rus' attack on Constantinople in 941, and the use of the spurs to smash the oars of the Rus' vessels. Boarding actions and hand-to-hand fighting determined the outcome of most naval battles in the Middle Ages.

One of the harbours of Constantinople, built by Theodosius on the Sea of Marmara

Chelandion () was a Byzantine galley warship, a variant of the dromōn that also functioned as a cargo transport.