" During the thirteenth century Genoese traders in the Black Sea port of Caffa struck a deal to run slaves captured in the Caucasus by the Mongols to the Mamluk rulers of Egypt, shipping them to the Nile Delta via the Black Sea and Mediterranean, whereupon the slaves would be forcibly impressed into the Mamluk army. Effectively this meant that the Christian Genoese were directly responsible for supplying workers to a power that was doing its best to crush the western crusader states of Syria and Palestine. "

― Dan Jones , Powers and Thrones: A New History of the Middle Ages