The Black Death also known as the Bubonic Plague was a massive, widespread plague that swept across Asia and Europe. It reached Europe in the late 1340s and continued for centuries. An estimated 25 million people died; one in 5 residents has died. Many people were killed by the plague if not injured and barely survived. The Black Death affected many people. The cause of the plague was thought to be the bacillus Yersinia Pestis, the deadliest disease of the Middle Ages. The process begins when the bacillus enters the bloodstream, eventually ending up in the lymph nodes. This causes the glands to become enlarged and inflamed, causing bumps to appear in the groin, armpit, or neck. Plague is transmitted by a rat flea that receives its bacteria from a mouse. Eventually, the flea spreads the disease to humans. The flea's stomach becomes completely filled with bacteria, preventing it from digesting blood anymore. The flea sucks blood into an already full stomach, forcing it to bring the ingested object back into its mouth which spreads the bacteria....