The term 'ancient warship' refers to two types of ships used in ancient times: the BIREME and the TRIREME. A BIREME was a two-leveled warship powered by oars, which was used by the Greeks and Romans in the Mediterranean Sea. It had two banks of oars, one on each side of the ship, and was propelled by up to 170 rowers. A TRIREME was a three-leveled warship powered by oars, which was also used by the Greeks and Romans in the Mediterranean Sea. It had three banks of oars, one on each side of the ship, and was propelled by up to 200 rowers. Both the BIREME and the TRIREME were used for naval warfare and were essential to the success of the ancient Greek and Roman empires.