Black Death

The Black Death, or Bubonic Plague, was a pandemic on Earth which became one of the most deadly pandemics in all of human history.

In the 14th century the disease began its spread in central Asia, and eventually made its way to Europe - where it was estimated to have killed between one and two thirds of Europe's population. In total the Black Death was estimated to have taken 75 million lives.

The immortal being Flint was in the Earth then known as Constantinople when the Black Death came to the city.

In the 23rd century, Commander Spock observed that if he had used Doctor Georges Mordreaux's time travel device to go back to Hikaru Sulu's favorite period in Earth history he'd be regarded as a heathen freak and given two choices on how to die. One would be through blood poisoning sustained when cut by a sword, and the other would be the plague.