In the year 1347, an epidemic disease arrived in Europe. Close to a century before, soldiers from the Mongolian Empire raided China, and upon their return, they unwittingly brought back foreign fleas carrying deadly bacteria embedded on their horses. Within decades, the virus began to take form and spread throughout the Silk Road, a merchant route running to the Black Sea. The Pandemic swept into Europe through rats and fleas which carried the deadly virus.
Several factors made the expansion of the virus possible. The flea that carried them lived on common rats that people generally see in their homes and cities. Trade ships entering northern Europe from the Mediterranean carried these rats into every port. Finally, the disease spread swiftly in Europe because of the heavily condensed population there.
The plague spread west from Constantinople and slowly went north. From Sicily, it infected France and crossed into the English Channel. Finally, it turned east, back towards Scandinavia and Russia. The Black Plague killed nearly 90 percent of all people it came in contact with. The exact number of deaths caused by the plague is not known. Historical records were not reliable and not always stored, but it is believed that nearly one-third of the entire population of Europe was exterminated.
Within a decade after this epic disaster, the human population came went through a rapid recovery. Though the plague was not over, birth rates were significantly high. In 1361, the plague returned but it particularly affected the younger generation, as they were never exposed to it before. Over the next century, the plague reoccurred every 5 to 10 years. Although they killed fewer people, it had stumped the human population and as a result, there was a decline in population between the 1350 and 1450. The Black Plague nearly prevented population growth and caused massive suffering. But, in a few decades, the population would rise back to its previous size.