The History of the Black Death in Europe
The first outbreak of the disease occurred in England during 1348-1349 and it is suggested that came to Europe from the town of Caffa on the Black sea. It is believed the plague originated in Asia and moved west with Mongol armies and traders. The Tartars had been struck by the disease and they were dying in huge numbers when they attacked the port city, during the war between the Muslim Tartars and the Christian Genoese.
The Tartars, blaming the Genoese for the disease, used huge catapults to fling plague-infected corpses into the city. Rotting corpses that filled the streets soon spread the disease in the city, killing the residents. The Genoese merchants decided to flee the city, jumped into their ships, and sailed to Italy, carrying rats and fleas that caused the disease, along with them.
When they reached Italy, the rats quickly spread to other ships and on to land where ships and traders carried the disease and spread it across the continent through Italy, France, England, Germany, and Denmark. The disease could have been contained if the people had remained in their cities, but in their haste to flee, they moved from village to village and across countries spreading the disease across land.
Trading ships that were infected managed to somehow make it to distant ports, but almost all the crew were dead and the people of the city, attempted to loot such ships and carried home items from the infected ship and helped to spread the disease. (Cartwright, 1991).