Black Death
In Crimea, Mongol forces were fighting for control of Caffa, a Black Sea port (now Feodosiya, Ukraine). At the time, Caffa was a Genoese trade centre. Mongol forces began a siege. During the siege, they are reported to have catapulted plague-infested bodies over the walls into the city. Genoans fled the siege by using ships. Some historians believe the Caffa refugees brought the plague back to Italy with them, which started the pandemic.