The term THREE-TIERED GALLEY is a type of ancient warship known as a TRIREME. It was used by the Greeks and Romans in naval warfare and had three levels of oarsmen, with one man per oar. The top level was the highest and most prestigious, while the bottom level was the lowest and least prestigious. The TRIREME was an important part of naval warfare in the ancient world and was used to great effect in battles such as the Battle of Salamis.