Quote Originally Posted by holybandit
Galley slaves were very very common.
No, galley slaves were extrmely uncommon if they existed at all. It has never been a good idea to have a lot of strong man row you into battle if they could stop anytime and hope their ship would be boarded and they would be set free. The practise to use prisoners as rowers dates back to at least 1532 and POW might have been used earlier. A simply lookup at wikipedia gave no information. Galleys of the greek or roman era were always manned by free man or at least slaves, who would be set free when their term was over.