Trierarch – a position in the ancient Roman navy, corresponding to the captain of a ship. Initially, only trier captains were called trierarchs, but over time the title of the position passed to captains of all types of ships. The trierarch was responsible for the combat readiness of his ship and for the successful completion of its combat mission.
The trierarch was subordinate to Navarch, who commanded the battle formation of the ships.