How did the Black Plague start and who discovered it?

The black plague started in 1347. The French biologist Alexandre Yersin discovered it.

The plague arrived in Europe in October 1347, when 12 ships from the Black Sea docked at the Sicilian port of Messina. People gathered on the docks were met with a horrifying surprise: Most sailors aboard the ships were dead, and those still alive were gravely ill and covered in black boils that oozed blood and pus.

Explanation:

in 550 b.c.e. cyrus the great, the leader of the persians, conquered the medes and united the iranian people under one ruler for the first time. cyrus became the first king of the persian empire and went on to establish one of the largest empires in world.