Trireme, an ancient kind of ship or rather galley, propelled, as its name denotes, by oars arranged in three tiers. The lowest bank of oars was the shortest, and the other two were of proportionately increasing length. In the Persian and Peloponnesian Wars the trireme was the largest vessel employed, but it was superseded by larger vessels, carrying four and five banks of oars. The Carthaginians and Romans used quinqueremes, and in the naval battle of Actium ships with nine and ten banks of oars were employed. In favourable weather rowing was aided by the use of a square-sail. In the earliest period of the trireme crews tried to grapple and then board the enemy but the Athenian method was to ram. Twenty sailors, as many soldiers, and a hundred and sixty rowers formed an Athenian crew.