Unlike the popular concept of galley slaves, ancient navies generally preferred to rely on free men to row their galleys. In the 4th and 5th century Athens generally followed a naval policy of enrolling citizens from the lower classes (the thetes), metics and hired foreigners. However, under some conditions, for example during the Mytilenean revolt, higher classes were enrolled as rowers also. This made them crucial in the Athenian Navy and therefore gave them a role in Athens' affairs (see Constitution of the Athenians).