A trireme was an ancient war galley, meaning that it was powered by oars as well as sails. The use of oars meant that the ship could be manoeuvred close to an enemy, and also it could still go forward at times of little wind. Slaves were used to work the oars.

The front end (prow) was sometimes fitted with a kind of battering ram, and was often highly decorated.

Triremes were floating battlegrounds, for archers would fire at each other from their decks.